There is little in the recent literature about the place of low molecular weight heparin (LMWH) in routine lumbosacral surgery.

This study aimed to determine firstly the risk of deep vein thrombosis (DVT) if Clexane was not given preoperatively, and secondly the complications associated with the use of the drug.

In a prospective study undertaken from January 2001 to April 2001, 64 patients scheduled for routine lumbosacral surgery were entered. We excluded patients with a high risk of DVT. The mean age of patients was 51 years (16 to 75). Patients were randomly selected to receive Endoxaparin (Clexane) preoperatively the night before (38 patients in group 1) or Clexane postoperatively (26 patients in group

2). All patients were evaluated by Doppler sonography pre-operatively, four days postoperatively and at six weeks. Blood loss was monitored intra-operatively and postoperatively. Clexane was administered only for eight days. Posterior lumbosacral spinal procedures only were done on 44 patients, while seven had combined anterior-posterior surgery and 13 anterior procedures only.

Mean intra-operative and postoperative blood losses in group 1 were twice those in group 2, and patients in group 1 tended to bleed for longer. Two cases of partial thrombosis were seen, both group 1. In group 1 intraspinal haematoma formation was seen in four patients, two of whom required additional surgery.

LMWH should not be given preoperatively for routine spinal cases. In fact, it is contra-indicated.

A retrospective study was done on the outcome of supracondylar femoral fractures treated with retrograde or supracondylar intramedullary nails.

Between January 1998 and December 2000, 69 patients were treated with Russell Taylor nails, 30 at Kalafong Hospital and 39 at Pretoria Academic Hospital. Injuries had resulted from motor vehicle accidents in 27 patients, from falls in 32 and from gunshots in 10. There were 13 open fractures and 14 patients had multiple injuries, including three head injuries and two vascular injuries. Using the AO classification, 40 fractures were graded type A and 29 type C. The mean age of the 18 female and 51 males was 45 years (17 to 90). Senior registrars performed the surgery. In all cases, the knee was opened for the procedure. Four patients died from their injuries.

The mean time to union was 13 weeks. Four patients had poor range of motion. Complications included two cases of superficial sepsis and three of deep sepsis. There were two cases of delayed union and three of fixation failure. In one patient the fixation impinged on the patella.

We find this a good way of treating supracondylar femoral fractures.

Purpose: Access to the cervicothoracic junction is difficult both via a posterior and via an anterior approach. Tumour localisations or more rarely trauma however require access. Using the posterior approach, anterior decompression is limited by the narrow access and the vulnerability of the cord. Anterior reconstruction is impossible. Using the pure anterior approach, fixation and decompression of the caudal component is limited. Preoperative MRI shows the respective position of the manubrium sternal and the diseased vertebra, allowing a clear surgical strategy. To avoid sternotomy or even partial cleidectomy, both causes of postoperative pain and complications, we developed a medial sternal resection maintaining the stability of the sternoclavicular joints and allowing spinal decompression by corporectomy to T3 and fixation to T4.

Material and methods: A left anterolateral cervical approach was used to avoid injury to the recurrent nerve. This is a classical cervical approach generally used for access to C7-T1. It is prolonged caudally a few centimetres on the mid line to reach the anterior aspect of the sternum. After section of the sternohyoid, sternothyroid and scapulohyoid muscles, the three upper centimetres of the sternum are resected with a microdrill over a width of two centimetres. This give direct access to the anterior walls of T3 and T4. The lower limit of the exposure is described by the aortic arch (except in patients with severe kyphosis). The left brachiocephalic venous trunk is the crucial element situated just horizontally behind the sternum and protected by fat and fibrous tissue. It is important to release this trunk precautiously because injury at this level is difficult to suture and would require ligature (this is still possible if necessary but would lead to oedema of the left arm by defective drainage). After releasing the vein, the resection of the posterior wall of the sternum is completed with a Kerrison gouge. This gives a U-shaped groove that does not destabilise the sternoclavicular articulations and allows retraction of the vessels to expose the vertebral bodies. Screw fixation of T4 is possible, generally with slightly descending screws. The classical closure method is used.

Results: We have operated 13 patients with tumours or fractures using this approach (five T4, seven T3, one T2). Corporectomy was performed above T4. This approach did not lead to any direct complications. Postoperative pain was considered to be less than with sternotomy or cleidectomy, approaches we have now abandoned. Use of the endoscope improves visibility but the incision cannot be smaller because of the axe required for screwing. The important features of this method are the correct analysis of the preoperative relation between the target vertebra and the manubrium sternal and the dissection of the left brachiocephalic venous trunk.

Purpose: We report an retrospective analysis of 33 patients with neurological para-osteo-arthroplathy of the hip who underwent surgery between 1985 and 1999.

Material and methods: Forty-three hips were operated in 33 patients aged 14 to 50 years at the time of the accident. Twenty-two patients had head trauma, two had spinal cord injury and three both. The causal mechanism was: trauma 27 patients, rupture of an inta-cranial aneurysm in five patients, widespread burns one patient. Localisations were inferome-dial 14 patients, anterior 10 patients, posterior two patients, circumferential five patients. Surgical care included complete resection in 30 cases, resection of the head and neck in six, and implantation of a total hip arthroplasty in seven. There were several perioperative accidents: two vessel injuries, two persistent bleedings, one haematoma, eight superficial infections, six recurrences, one ankylosis and one death. Functional outcome was assessed on the basis of gain in amplitude of hip flexion.

Results: Analysis was possible for 37 of the 43 hips. Outcome was good in 18 (flexion gain greater than 90°), fair in nine (flexion gain from 60 to 90°), poor in ten (flexion gain less than 60°). Complete resection gave better results (61.5%). Total hip arthroplasty gave mediocre results. The best results were obtained with resection for the inferomedial and anterior localisations.

Discussion: The decision for surgery should be discussed in light of the objectives to be achieved. We present our surgical strategy as a function of the localisation. We advocate systematic verification of the vascularisation and prefer the obturator approach for inferomedial localisations. The risk of recurrence depends on the delay from the accident to surgery.

Conclusion: Based on this retrospective series, we prefer surgical resection after the first year. We emphasise the importance of peroperative verification of the vascularisation.

Background: Non-union of fractures is a common problem faced by orthopaedic surgeons. Although the basic processes of fracture healing have been better elucidated in recent years, in terms of their cellular and molecular biology, the pathogenesis of fracture non-union remains poorly understood.

Aims: To examine the pattern of cytokine expression in established non-unions, in particular the inflammatory cytokines interleukin 1 and tumour necrosis factor alpha.

Materials and Methods: Tissue was taken from 7 non united fractures at the time of a surgical procedure aimed at effecting union. Part of the tissue was snap-frozen in liquid nitrogen, and a portion of the sample was processed for routine histology. Normal bone tissue was taken from the femoral shaft at the time of arthoplasty, to provide normal control tissue. Total RNA was extracted from the frozen tissue by means of a mortar and pestle and a modified phenol-chloroform extraction protocol. Cytokine expression patterns were examined using the Cytokine Gene Expression plate I (PE Biosystems) and analysed using the Sequence Detection Software and Microsoft Excel.

Results: A consistent pattern of cytokine expression was seen in all non-union tissue samples. There was marked suppression of interleukin 1 beta, interleukin 8, interleukin 10 and TNF-alpha when compared to resting bone. This environment is thus one where the stimulus for bone resorption is suppressed, with consequent loss of stimulation of bone formation (theory of “bone coupling”), directly and also possibly through interaction with prostaglandin production. In addition, collagen production is stimulated preferentially. These findings argue against the traditional definitions of fracture non-union, and suggest a possible adjunctive role for the administration of interleukins in the treatment of non-united fractures.

The worldwide increase in the resistance of micro-organisms to antimicrobial drugs leads to an increase in morbidity, mortality and health care costs. It is important to identify the resistant organisms, to provide alternative antibiotic treatment protocols and to identify the high-risk infection areas.

We undertook a retrospective study of 693 musculoskeletal infections seen in the Musculoskeletal Tumour and Sepsis Unit of Pretoria Academic Hospital over five years, capturing data relating to the microscopy, culture and sensitivity to antimicrobial drugs of micro-organisms from tissue samples and pus swabs.

Most infections developed in patients aged 31 to 40 years. Sepsis most often occurred postoperatively. The next most common sepsis followed trauma. The femur was the most common site, followed by the tibia and the knee. In descending order, the most common organisms isolated were Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas sp., Escherichia coli, Enterobacter sp.

In the last two years there was an alarming increase in coagulase-negative staphylococci. All micro-organisms exhibited increased resistance to specific antimicrobial drugs over the five-year period.

Purpose: The long Arnold nerve can be compressed at several sites. We analysed retrospectively eight patients who underwent surgery for Arnold’s neuralgia between January 1998 and June 2000. The purpose of our analysis was to determine the results of the neurolysis technique.

Material and methods: There were seven women and one man, mean age 52 years. Pain had progressed for more than one year (mean 3.5 years) and all patients had participated in long rehabilitation programmes. All had had at least one radioguided posterior injection at the C1–C2 level. Bilateral neurolysis was performed for patients with bilateral pain. The same surgical technique was used for all patients: desinsertion of the inferior oblique muscle from the lateral aspect of C2 and neurolysis of the posterior branch of C2 to the lower border of the inferior oblique muscle. When needed because of major osteoarthritis, C1–C2 fusion was achieved by posterior lacing.

Results: There were no per or postoperative complications. Neuralgia improved in all patients (70/100 to 20/100 on visual analogue scale). Pain relief was considerable for one female patient who had associated C1–C2 osteoarthritis. One patient complained of posterior joint pain at last follow-up. an anatomic cause of the compression was identified in three cases: osteophyte on the posterior part of the C1-C2 articulation, hypertrophy of the periradicular venous plexus, and passage of the Arnold nerve within the inferior oblique muscle with compression in a fibromuscular sheath.

Discussion: Several methods have been proposed to relieve Arnold’s neuralgia. Rehabilitation exercises and injections should, in our opinion, be attempted first. The Sturniolo procedure (unique desinsertion of the inferior oblique muscle) would be insufficient. We prefer to associate neurolysis at the C2 level because of the frequently associated anatomic anomalies.

Conclusion: Different sites can be involved in the compression of the Arnold nerve, warranting associated neurolysis.

During the last four years the author has used extracorporeal shock wave therapy (ESWT) to treat tendonoses, including 82 cases of tennis elbow, 108 cases of plantar fasciitis and 42 cases of related conditions. Treatment is administered in the consulting room without analgesia. This paper discusses the protocol used in selected cases.

In 78% of cases, overall subjective and objective results were good to excellent, in 15% fair. In only 17% was the result poor, with no improvement. No cases of degeneration were encountered. There were few complications and these were minor. Because of the obvious clinical benefits in selected cases, this new modality of orthopaedic treatment is still being used daily after four years.

Purpose: Among 80 surgical treatments for acetabular fracture, the Dana Mears approach was used in 15. The purpose of this study was to analyse functional and radiological outcome of these fractures at a mean follow-up of 41 months.

Material and methods: The AO classification was used for fractures of the acetabulum : 12 class B (80%) with five B1a2 five B2a1 and two B1a1, and three class C (20%). There was one deformed callus (B1a2) at 120 days Two patients had associated pelvic injuries, eight a hip dislocation, and two an initial sciatic palsy. There were also two osteochondral fractures of the femoral head. The Dana Mears approach was modified slightly in the anterior part passing in front of the tensor muscle to preserve innervation. The gluteal muscles were raised by trochanterotomy. The displacement, the head/ roof congruency and the head/acetabulum congruency were assessed according to the 1981 SOFCOT criteria on the initial x-rays (AP pelvis, oblique ala and obturator) and computed tomographies. The quality of the reduction was assessed with the Matta and Duquesnoy-Senegas criteria. Clinical results were assessed with the Postel Merle d’Aubigné (PMA) score.

Results: Radiographically, there was an anatomic reduction in 73.3% of the cases and perfect head/roof congruency in 80%. Functional outcome was excellent or good in 80% of the patients. Postoperative complications included 11 ossifications, and one transient sciatic paralysis. There was one late aseptic osteonecrosis of the femoral head.

Discussion: The functional prognosis of these fractures is significantly correlated with the quality of reduction (p < 0.05). The advantage of this approach is the direct access to the roof without disinsertion of the gluteal muscles from the iliac crest, allowing more rapid recovery (seven to eight months) of medius gluteus function. In principal drawback is the very high rate of ossifications (one patient required revision for arthrolysis).

Conclusion: The Dana Mears triradiate approach is an integral part of the surgical treatment of acetabular fractures, particularly for B1a2 and B2a1 fractures, but also for B1a1 transtectal fractures. Conversely, this approach is insufficient for reduction of type C fractures requiring and extensive access to the iliac wing and for surgery of deformed calluses where an endopelvic approach is indispensable to control the vessels.

Osteoarthritis of the hip exhibits progressive degeneration of articular cartilage frequently resulting in total hip arthroplasty (THA). Expression of cytokines such as tumor necrosis factor alpha (TNF-alpha) and interleukin 6 (IL6) is increased in the synovium and articular cartilage of these patients. Furthermore, these cytokines have been shown to have a negative regulatory effect on chondrocyte proliferation and articular cartilage metabolism. We investigated the frequency of a G/C polymorphism at position −174 of the promoter region of the IL-6 gene and a G/A polymorphism at position −308 of the TNF alpha gene, both of which cause increased expression of these cytokines. We observed that the G variant of the IL6 gene was significantly higher in patients who had undergone revision THA compared to controls (P=0.05). It was also elevated in primary THA patients compared to controls. The G/A polymorphism in TNF alpha was not significantly associated with THA; however, this may reflect the lower incidence of this polymorphism in the population. These results suggest that an alteration in cytokine expression produced by the IL6 −174G/C mutation may have a role in the aetiology of osteoarthritis and the outcome of total hip arthroplasty.

Introduction: Cement removal in revision total hip arthroplast;y can be technically challenging. Traditional methods can be associated with femoral fracture or uncontrolled cortical perforation and bone loss. A new technique has been developed tha.t permits segmental extraction of bone cement from the femoral canal. Fresh cement is introduced into the old cement mantle and a threaded rod is placed into the wet cement and held in place while the cement hardens. The thread-forming rod is then removed leaving a threaded channel in the cement. Extraction rods are then screwed 1.5 to 2.5 cm into the threaded channel. A slap hammer, which attaches to the opposite end of the extraction rod, is used to remove 1.5- to 2.5-cm segments of cement. The old cement – cancellous bone interface fails before the new-old cement interface and the old/new cement is removed in segments. This allows minimal removal of cancellous bone.

Patients and Methods: Patients who had contra-indications to segmental cement removal such a discontinuous cement mantle were excluded. Twenty-five consecutive cases of revision arthroplasty were entered into the study. The indications were for aseptic loosening in twenty-three cases and deep infection in two cases.

Results: In twenty-two cases the cement was removed completely. In five cases the cement was removed en-bloc in one single extraction rather then in segments. In two cases there was failure of the new cement to bond to the original cement and alternative methods were used. In a further case the cement was removed using a combination of segmental and conventional techniques. There were no cases of cortical perforations or perforaltions in this series. We have found it to be a reliable and safe method of cement removal. The cost of the system is offset by reduced operative time and blood loss.

A non-invasive technique for labelling S phase osteoblasts in vitro following immunolabelling of their focal adhesions is proposed. Quantification of cell adhesion area in the S phase (where the cells are most spread) of the cell cycle is then possible with a scanning electron microscope (SEM).

Primary calvarial osteoblasts (isolated by migration) were cultured on plastic and implant quality metal discs. S-phase cells were labelled by a pulse of 3H thymidine in the culture medium for 30 min. Cells were cultured for a further 2h in normal media before being processed for immunogold labelling of vinculin. Briefly, cells were permeabilised and fixed in 4% paraformaldehyde. Non specific binding sites were blocked for 30 min. Cells were incubated with mouse anti vinculin for 1h before rinsing and blocking with 5% goat serum for 30 min. Secondary incubation was with goat anti mouse 5nm gold conjugate for 2h. After rinsing, cells were permanently fixed with 2.5% glutaraldehyde. For SEM visualisation, the gold label was enhanced with gold enhance solutions. Postfixation and staining was performed with osmium tetroxide. Samples were dehydrated and critically point dried. The discs were carbon coated and covered with a thin layer of photographic emulsion in a dark room and left in a light tight box at 4°C for 7 days before developing the emulsion.

Backscattered electron imaging with the SEM revealed silver grains on the nuclei of S-phase cells, produced by the interaction of radioactive emissions, from the labelled DNA, and the photographic emulsion. Immunolabelled focal adhesions were also observed at higher magnifications on the same cells.

This combination of autoradiography and high resolution SEM removes cell cycle variability, which has been a problem with previous in vitro adhesion studies. This method will be applied to quantify osteoblast cell adhesion to various implant materials to evaluate cell/implant interactions.

The changes occurring in ligamentum flavum in lumbar spine stenosis are a matter of long–standing controversy. More recently, some studies showed that the posterior spinal structures, including hypertrophied ligamentum flavum, play a major role in the pathogenesis of the lumbar stenosis.

To investigate the pathogenesis of the degenerative changes of the ligamentum flavum occurring in lumbar spine stenosis, yellow ligament cells from patients with lumbar spine stenosis were cultured for the first time and subjected to biochemical, histochemical and immunohistochemical study.

Samples of ligamentum flavum were collected from 4 patients undergoing surgery for lumbar stenosis (mean age 47.2 years). Cell cultures were obtained from each patient and maintained in Dulbecco’s modified essential medium-10% fetal calf serum. Cell characterization was histochemically (Gomori’s and von Kossa staining), immunohistochemically (anti-type I, -type II, -type III and -type X collagen, anti-S100 protein, anti-fibronectin, anti-osteonectin and anti-osteocalcin), biochemically (cAMP activity after human parathyroid hormone stimulation) assessed. Samples collected from 2 age-matched patients who underwent surgery for lumbar fractures were used as controls.

Stenotic ligamentum flavum cells expressed high levels of alkaline phosphatase activity and produced a mineralized matrix rich in type I, type III and type X collagen, fibronectin, osteonectin, and osteocalcin. Stimulation with parathyroid hormone increased intracellular cAMP concentration. These findings indicate that there was significant evidence of osteoblast-like activity in these cells. Staining for type II and type X collagen, and S-100 protein reflected the proliferation of hypertrophic chondrocyte-like cells, confirmed with the co-localization of alkaline phosphatase and collagen type II. Cultures from control patients showed nor hypertrophic chondrocytic nor osteoblastic features. Our data demonstrated the presence of hypertrophic chondrocytes with an osteoblast-like activity in human stenotic ligamentum flavum. The osteoblast-like activity could have a role in the pathophysiology of the heterotopic ossification of ligamentum flavum in lumbar spine stenosis.

Purpose: Bilateral hip disease is a common finding. For patients in good general health the question is whether total hip arthroplasty should be performed on both sides during the same operation or whether a deferred strategy would be better. We compared 24 patients (48 hips) to determine the relative advantages of these two treatment strategies.

Material and methods: Two treatment groups were formed: the first group (group A) was a prospective series of 12 patients who underwent total hip arthroplasty for both hips during the same operation between January 1992 and September 1999; the second group (group B) was composed of 12 patients who had total hip arthroplasty for both hips implanted during two different operations separated by at least one year and chosen by random selection among patients operated during the same period as group A patients. Group A was composed of five women and seven men, mean age 48.4 years (23–67). Group B was composed of five women and seven men, mean age 60 years (50–75). Pressfit cups were used in both groups (except one in group A). The femoral stem was cemented in seven patients in group A and in five in group B. Peroperative data (transfusion, complications, anaesthesia agents, duration of anaesthesia and operation) and post-operative data (transfusions, blood loss, haemoglobin, temperature curve, hospital stay, drugs, early and late complications, radiologic findings) were studied. LWMH was given prophylactically and all patients had a duplex Doppler exploration before discharge. All patients were reviewed regularly: mean follow-up was 5.75 years (2–9) in group A and 6.42 years (2.33–8.5) in group B.

Results: We added the two hospitalisations for group B patients. Mean duration of the operation was 6h in group A and 4h22m in group B. Anaestheia lasted 7h in group A and 6h16min in group B. Blood transfusions amounted to 5.27 packed cell units and 3.09 fresh frozen plasma units in group A, 4.75 and 2.83 respectively in group B. Blood loss was 1439 cc in group A and 1642 cc in group B. Haemoglobin and temperature curves were similar between the two groups. There were two cases of postoperative phlebitis in group A and one revision procedure on day 9 for haematoma in group B. There were no cases of infection. Mean hospital stay was 14.66 days in group A and 22.5 days in group B. Radiographs did not show evidence of loosening.

Discussion: The results obtained in our two series are similar to other reports in the literature (Eggle 1996, Shih 1985). Per- and postoperative complications were not more frequent for one or two procedures. Hospitalisation stays were much shorter in group A patients, providing an important cost savings (34.8% for simultaneous implantations).

Conclusion: Bilateral total hip arthroplasty during a single operation offers an advantage in terms of hospital stay and overall cost. Comparison with two different operations shows that complications are not more frequent. Inversely, work stoppage is shorter, making this strategy particularly interesting for younger patients.

The purpose of this study was to evaluate the safety of liquid collagen and cross-linked collagen in treating bone defects.

In a prospective trial, the use of liquid collagen and a stiffer, slightly more rigid cross-linked collagen allograft was evaluated. Bone cavities resulting from curettage of cysts or tumours were filled with either liquid or cross-linked collagen. The collagen was extracted from donor allograft and mixed with minute particles of crushed cortical bone. Patients were monitored clinically, radiologically and haematologically for complications, including infection, rejection or allergic reactions.

There were five patients with osteoid osteoma, five with chondrosarcoma, two with bone cysts, five with osteitis and three with chondroblastoma. One patient each had enchondroma, ossifying fibroma, osteosarcoma, aneurysmal bone cyst, fibrous dysplasia, thickening of the tibial cortex, avascular necrosis, Ewing’s sarcoma, a luxstacortical ganglion and a tumour of the pubic symphysis. Eleven patients received liquid collagen and 32 cross-linked collagen. The use of liquid collagen was abandoned because it was too fluid to keep in the cavity. The cross-linked collagen, though more solid, could be introduced even through small holes in a bone or spinal cages. No allergic reactions occurred and the bone graft behaved similarly to a combination of allograft/autogenous graft.

Cross-linked collagen is as effective as any other allogenic bone product in bone cavities. In this series there were no complications attributable to the graft.

Background: Neutrophil (PMN) infiltration of the lung is characteristic of ARDS. Interleukin-8 (IL-8) plays a central role in the recruitment of PMN to the lung and their subsequent activation. This study examines PMN migratory activity in response to IL-8, over the first 24 hours of admissions following major trauma.

Methodology: Study Population: Adult blunt trauma victims with ISS> /=18

PMN Migraoty Activity: PMN were isolated from citrated blood at admission, 8 and 24 hours later. The number of PMN migrating across porous tissue culture inserts in response to defined concentrations of IL-8 (zero, 10, 30 & 100ng/ml) were quantitated by peroxidase assay.

Results: Significantly greater numbers of trauma patients PMN migrated to concentrations of IL-8 (30& 100ng/ml) at each time point, when compared to normal volunteers (Mann-Whitney-U Test p< 0.05). At admissions, and 8 hours later, PMN from those who later developed ARDS exhibit an enhanced migratory response to high concentrations of IL-8, in contrast to the noraml physiological attenuation of migration seen in both the remaining trauma patients (NAD) and normal volunteers (NLV).

Discussion: These data indicate that major trauma fundamentally alters the migratory capacity of circulating PMN. Within 2 hours of admission, PMN show a unique pattern of activation in those who later develop ARDS, possibly due to alteration in IL-8 receptor expression, affinity or downstream signalling. These findings suggest that limiting PMN sequestration in the lung may represent a novel therapeutic target.

Fractures and fracture dislocations involving the lower lumbar spine and lumbosacral junction are uncommon. These high velocity injuries are often associated with neurological deficit, incontinence and dural tears. The accepted treatment has been posterior stabilisation with fusion, but loss of reduction has often been reported.

We reviewed our experience over the past four years in the management of eight male patients, two of whom sustained injuries in motor vehicle accidents and two in falls from a height. Two patients had L5/S1 traumatic spondylo-listhesis with no neurological deficit. Of the six patients with fracture dislocations of L3/4, four had translation in the sagittal and coronal planes and incomplete neurological deficit. Associated injuries in four patients included an ankle fracture, multiple rib fractures, dislocation of knee and hip, and a fracture dislocation of the midfoot.

Following satisfactory reduction, seven patients were treated by posterior spinal fusion (PSF) with instrumentation. One patient had anterior decompression, strut-grafting and posterior instrumentation. Three patients had dural tears.

In three patients treated by single segment PSF, reduction was not maintained. The maintenance of alignment was attributed to stable facet joints in one patient, two-segment instrumentation in three, and anterior strut grafting in one. One patient developed postoperative wound sepsis, which settled after repeated debridement and antibiotic treatment. Symptoms of nerve root compression improved in two of the four patients with neurological deficit.

Posterior reduction and instrumentation alone did not maintain reduction in these severe injuries. Anterior column support and multisegmental instrumentation may be required where there is marked vertebral body compression and neurological deficit.

Systematic reviews show beneficial effects of spinal manipulation, general exercise, and ‘active management’. A national randomised factorial trial in primary care (UK BEAM trial) was designed to evaluate the effectiveness of these treatments for back pain. We will present the characteristics of participants recruited into the trial and preliminary health outcomes at one and three months.

Back pain patients, recruited from over 150 UK practices, were randomised to receive GP management, exercise classes, manipulation (either in NHS or private premises) or both manipulation and exercise classes. At one, three and twelve months, participants completed postal questionnaires which included questions about general health, experience of back pain, beliefs about back pain, psychological profile, functional disability and costs to both the NHS and the participants themselves.

The trial recruited 1334 participants, of which 84% and 77% completed one and three month questionnaires respectively. At randomisation, the mean Roland Disability Questionnaire (RDQ) score was 9.0 points (sd=4.0). This improved to 6.8 points (sd=4.8) at one month and to 5.5 points (sd=5.0) at three months.

Preliminary blinded results show an improvement in RDQ scores across all participants. The primary analysis, available late in 2002, will estimate the main effects of exercise and manipulation, each compared to GP care.

Purpose of the study: We compared in vitro the efficacy of screw-plate fixation versus double screw fixation on a model of type 2 Schatzker fracture of the lateral tibial plateau.

Materials and methods: Ten screw-plate fixations using a lateral prebent plate and 10 double-screw fixations (6.5 mm screws) were made on 10 pairs of non-embalmed cadaver knees after simulation of type 2 Schatzker fractures. The strength of each fixation was tested with a compression device. Criteria indicating failure were displacements greater than 2 mm of one or more fracture lines. The force applied at rupture and the stiffness of each type of fixation were compared. Wilcoxon’s test was used for statistical analysis.

Results: Force at rupture and stiffness of the fixation were similar for the two types of fixation. There was no statistical difference (p > 0.05) between the screw-plate and the double-screw fixations.

Discussion: Our findings on a model of type 2 Schatzker fractures are in agreement with previous data obtained by other authors working on models of type 1 Schatsker fractures. The biomechanical stability of the double-screw fixation is as good as that obtained with screw-plate fixation for the treatment of fractures of the lateral tibial plateau.

Purpose of the study: Equinus in patients with cerebral palsy results from at least two factors: excessive contracture of the triceps surae and muscle retraction. Tendon surgery and progressive lengthening techniques using plaster walking boots can provide variable improvement in retraction. We compared the effect of this technique when applied with or without prior 40°C warming in the same patients. We also assessed the efficacy of this treatment method in terms or degree of retraction, patient age, puberty maturity, and sex.

Materials and methods: This series included 70 muscles in 52 patients with cerebral palsy aged 2 years 11 months to 21 years (mean 8 years 3 months). Common features in these patients were: equinus mainly explained by triceps retraction, no history of prior surgery on the triceps tendon, knee flexion less than 15° in the upright position, easily reduced lateral deformation of the foot, absence of mediotarsal dislocation, triceps stretching could be achieved without triggering unacceptably intense contracture.

The retraction of the triceps surae was measured from the maximal passive dorsal flexion angle of the foot, before and after applying each stretching boot. The difference between these measurements gave the gain obtained with the plaster boot. Protocol R− (stretching with plaster boot) consisted in a series of slow stretchings for 10 minutes before making the boot which was worn 7 days. Recurrent retraction in these same patients warranted another treatment within a delay of 3 to 17 months (mean delay 8.7 months). The same treatment then followed protocol R+ where the stretching was preceded by immersion of the segment in a 40°C water bath for 10 minutes.

Results: Mean gain obtained with protocol R+ (warming) was 6.8° knee extended and 7.1° knee flexed. These differences were highly significant in both cases (p < 0.0001). We had no failures with protocol R+ while with protocol R− (stretching without warming) the gain was nil or less than 5° for 29 muscles knee extended and for 32 muscles, knee flexed. The gain was not related to age, sex or puberty maturity. It was not related to the angle of dorsal flexion of the foot prior to stretching.

Discussion: Our findings demonstrate that when the conditions allowing prolonged stretching of the triceps surae are present, prior warming at 40°C for 10 minutes leads to an improvement in muscle lengthening in all patients, even in those for whom prior treatment had been unsuccessful without warming. This observation would indicate that the mechanisms allowing greater lengthening are present in all patients with cerebral palsy but that they cannot be triggered due to abnormal muscle viscosity related to distal vasomotor disorders frequently observed in this condition. Further research is needed to detail this point.

Purpose: This retrospective analysis was performed to determine the long-term usefulness of carpectomy and to define prognostic factors.

Material and methods: Forty-four patients were operated. There mean age was 39.2 years, and mean follow-up was 17 years (10–35 years). Twenty-two patients had osteoarthritis, one STT, thirteen SNAC-wrist, two SLAC-wrist, and three radiocarpal osteoarthritis. The wrists were free of degenerative lesions in 22 cases: eight Kienböck disease, five longstanding perilunar dislocations, six fracture sequelae, and one rheumatoid polyarthritis. Seventeen patients had had several procedures before the present operation. The dorsal approach was used for all patients except five. Complementary styloidectomy was associated in two cases. clinical and radiological outcome was assessed at one, five and fifteen years. Factors predictie of outcome were analysed with the Student test and the Man and Whitney test.

Results: The pain score (Cooney scale 1 to 4) was 3.19 preoperatively and 1.56, 1.88 and < 2 at one, five and fifteen years respectively. Flexion amplitude improved from 44° preoperatively to 61°, 68° and 62° at one, five and fifteen years respectively. Mean grip force, compared with the other wrist was 57.5%, 75% and 64% at one, five and fifteen years. Radiographically, at fifteen years 80% of the patients had a centred capitatum on the AP view of the lunar facet. On the lateral view, 56% of the patients exhibited anterior translation of the apitatum and 37% were centred. There was a degradation of the radiocapitum space requiring revision for arthrodesis in five cases.

Discussion, conclusion: This study confirms the long-term preservation of outcome after proximal carpectomy: 89% of the patients were satisfied at fifteen years. These findings also indicate that reconstruction of recent trauma (fracture-dislocation) produces variable results. For patients with grade II or II osteoarthritis (SNAC or SLAC-wrist) carpectomy should be reserved for selected patients with occupational or sports activities not requiring grip force. For grade III wrists, carpectomy can be proposed for elderly patients with limited activity. Grade IV is a contraindication for carpectomy. We do not recommend this procedure for patients with rheumatoid arthritis or Kienböck disease.

Purpose of the study: We report a case of complete unilateral absence of the radial artery in the forearm and reviewed the pertinent literature.

Case report: An 18-year-old girl was admitted for multiple fractures after a car accident. She presented with a comminuted fracture of the left distal humerus, an open grade I fracture according to the Gustilo classification involving the right ulna and radius, a mediodiaphyseal fracture of the right femur and an open grade II fracture of the proximal and distal left tibia. After open reduction and internal fixation of the bones of the right forearm, she presented transient ischemia of her right hand, the radial pulse not being detectable at the end of surgery. An arteriography showed a complete absence of the right radial artery, which was thought to be caused by arterial thrombosis. Surgical exploration evidenced the complete absence of the radial artery.

Discussion: Absence of the radial artery is observed in radial preaxial hemimelia, in specific genetic and chromosomal disorders (Fanconi’s anemia, Holt-Oram syndrome) and in association with other malformations. Unilateral absence of the radial artery has been described in association with other vascular abnormalities such as a larger anterior interosseous artery or the presence of a medial artery. Our case presented an isolated anatomical variation of the radial artery. This vascular anomaly was asymptomatic and discovered fortuitously. The incidence of this anatomic anomaly may be underestimated in the general population.

The success of lumbar spine fusion depends on good patient selection and bone grafting technique. Instrumentation of the fusion, now popular, improves fusion rates, eliminates the need for postoperative braces and allows early mobilisation. However, the stress shielding caused by rigid internal fixation is thought to lead to osteopoenia and degeneration of adjacent segments. Theatre times, intra-operative complications and costs are increased when pedicle screw fixation is added.

This is a report of a pilot study of eight patients who had one-level fusion and unilateral instrumentation between 1998 and 2000. Theatre time, fusion rate and functional outcomes were evaluated. The minimum follow-up time was eight months. Fusion was achieved in all patients and there was no metal failure. One patient continued to have back and leg pain in spite of a solid fusion.

Although this is a small study undertaken over a short period, the results suggest that unilateral pedicle screw fixation can be safely undertaken.

Purpose: We report our experience with acetabular reconstruction using cyropreserved bone bank hemipevli without a scaffold and total hip arthroplasty for major acetabular defects. Between 1985 and 1999, among 262 acetabular reconstructions requiring massive allografts using cryopre-served bone, 20 cases were performed with hemipelvi.

Material and methods: Mean age of the population was 56 years. The acetabulum had been operated on a mean three times. The 20 defects corresponded to Paprosky grade IIIB or SOFCOT grade IV bone loss. Clinical and radiological review of the 20 hips was made at a mean five years after treatment. None of the patients was lost to follow-up. The overall Postel Merle d’Aubigné (PMA) score at last follow-up was 17 for preoperatively scores at D2, M4 and S3 respectively. The acetabular defects were major and poorly described by the conventional systems. For example, the mean height of the bony defects was about 10 cm measured from the base of the radiographic U and the superolateral rim of the remaining roof.

Results: Globally, 13 patients had not required a reoperation at last follow-up. We had one postoperative death and two early displacements as well as two infections including one haematogenous infection. The Oakeschott criteria were used to analyse the review radiographs. Aseptic lysis of the graft was observed in five cases (generally around the 13th postoperative month) that required revision; a bone graft and a supporting ring were used in all cases because more bone stock was available than for the first revision. Among the 13 cases that did not require a new procedure, there were two with an ascended graft displacing the centre of rotation about 10 mm, followed by radiographic stability. The overall functional score for these 13 hemipelvi at last follow-up was 17 demonstrating the superior functional result compared with arthroplastic resection, the only alternative for such important loss of bone stock. It is not possible to implant a large non-cemented socket in these cases. Radiographic fusion was achieved, documented in 13 cases by the development of bony bridges or disappearance of the interface with oriented lines of force. Early graft resorption does not appear to occur when a metallic scaffold is associated (Garbuz).

Discussion: In all, 19 hips still had their total arthroplasty at last follow-up (one patient with failure preferred trocahntero-iliac coaptation.

Conclusion: Due to the inefficacy of alternative methods, this mode of restoration for major bone loss of the acetabular region (which facilitates secondary revision) appears to provide satisfactory results since the probability of preserving the prosthesis at a mean five years was slightly greater than 3/5. A stronger metallic scaffold may be the solution for the future.

We looked at the outcome of management of 16 patients (19 limb segments) with congenital fibular hemimelia treated in our unit over a 24-year period from 1978 to 2001. Eight boys and eight girls, all with associated musculoskeletal abnormalities in the lower limbs, were presented for management at or before the age of six months.

On four patients no surgery was performed. In the other 12, orthopaedic management was completed during the skeletal growth period. Primary amputations (one below-knee, one Syme and one Boyd) were performed on three patients and prostheses fitted in early childhood. Three patients with bilateral fibular hemimelia were treated initially with a Gruca ankle reconstruction procedure. Using the Ilizarov technique, we performed tibial lengthening procedures on nine patients.

At the latest follow-up, the three patients who had amputations were functioning well and had no complications. The nine patients in whom tibial lengthening was the main reconstructive procedure suffered numerous complications and all needed further corrective surgery or footwear alterations. None required or requested late amputation because of poor function or cosmesis. Analysing results by parameters such as restriction of activity, pain, complication rate, treatment costs, hospital and clinic visits, periods of absence from school, and patient satisfaction, we found notably better results among patients who underwent early primary amputation than among those who underwent tibial lengthening.

This needs to be kept in mind when advising parents of the most appropriate course of management of their child’s disorder.

Injury to the infrapatellar branch of the saphenous nerve has been reported as a complication of arthroscopic examination and surgery of the knee. This can result in altered sensation on the anterolateral aspect of the knee, reflex sympathetic dystrophy and, occasionally, severe deafferentation pain. The aim of this cadaveric study was to delineate the course of the infrapatellar branch as it passes across the anterior aspect of the knee and identify potential safe areas for blind puncture at arthroscopy. The risk of damage to the nerve branch from the various open incisions used for orthopaedic surgery of the knee is also discussed.

The distribution of the infrapatellar branch was studied in both lower limbers of eleven cadavers (22 specimens). Two patterns of nerve distribution could be described in relation to its path across the proximal margin of the tibia. In 28% of examined cadavers, the infrapatellar branch of the saphenous nerve traverses the patellar tendon and runs laterally without ever crossing over the tibia. In the remaining 72% the infrapatellar branch crossed the proximal margin of the tibia prior to crossing the patellar tendon. Using the interior pole of the patella as a landmark, our results indicated that blind puncture is safe within an approximate wedge-shaped area ranging from 10mm inferior and 30mm medial to the inferior pole up to a level 10mm superior and 50mm medial to the inferior pole of the patella. The incidence of injury to this nerve can be reduced by clarifying the distribution of the infrapatellar nerve branch in relation to palpable landmarks.

Purpose: We have sometimes observed paralysis of the long portion of the triceps in patients operated after traumatic damage to the axillary nerve. In anatomy textbooks, the motor branch of the long portion of the triceps arises from the radial nerve within the triceps. We studied the position of the motor branch of the long portion of the triceps in order to better detail its origin.

Material and methods: Group I: this group included nine patients with trauma-induced lesions of the axillary nerve associated with clinical involvement of the long portion of the triceps. Group II: this group was composed of 20 cadaver specimens of the secondary posterior trunks. Group III: fif-teen approaches to the subclavian plexus with dissection of the secondary posterior trunk. Lesions to the axillary nerve were retrieved from the operation reports in group I. The origin of the motor branch of the long portion of the triceps was identified in group II. The same origin was identified by neurostimulation in group III.

Results: In group I there were six lesions of the axillary nerve situated a mean 10 mm from the division of the secondary posterior trunk and three lesions of the secondary posterior trunk. There were four type IV lesions and five type V lesions. In group II, the motor branch of the long portion of the triceps arose a mean 6 mm from the division of the secondary posterior trunk in 13 cases, at the division in five cases, and 10 mm downstream in two cases, but never from the radial nerve. In group III, the branch of long portion of the triceps arose a men 4.5 mm from the division of the secondary posterior trunk in 11 cases, and at the division in four cases, but never from the radial nerve.

Discussion: In patients with trauma to the axillary nerve with paralysis of the long portion of the triceps, lesions to the axillary nerve occur proximally and are severe. In our study, the motor branch of the long portion of the triceps always arose from the axillary nerve or the secondary posterior branch. This shows that paralysis of the long portion of the triceps is a sign of poor prognosis in patients with traumatic lesions to the axillary nerve. This association is for us an element in favour of a proximal and serious lesion to the axillary nerve.

Conclusion: Involvement of the long portion of the triceps must be searched for in patients with traumatic lesions to the axillary nerve. Paralysis of the long portion of the triceps is a sign of a serious lesion requiring early surgical repair before two months.

Purpose: Radial paralysis is a major complication of humeral shaft fractures. In most cases, the paralysis is regressive but in certain patients surgical repair is required to achieve full neurological recovery. We reviewed retrospectively our patients to determine the causes of non-recovery and evaluate the efficacy of different treatments.

Material and methods: Thirty patients were operated between 1990 and 1997 for radial nerve paralysis that was observed immediately after trauma or developed secondarily. Mean follow-up after surgery was 6.3 years. There were 22 men and 8 women, 16 right side and 14 left side. Mean delay from injury to surgery was four months (0–730 days). Elements that could be involved in radial paralysis were noted: type of fracture, level of the fracture, treatment, approach, material used. There were ten cases with non-union. Neurological recovery at three years was assessed with muscle tests and with the Alnot criteria. An electrical recording was also made in certain patients. Surgery involved neurolysis in 23 cases, nerve grafts in five and tendon transfers in two.

Results: Outcome was very good and good in 22 patients, good in one and could not be evaluated in one (tendon transfer). There were three failures (two neurolysis and one graft) and two patients were lost to follow-up. After neurolysis, mean delay to recovery was seven months; it was 15 months after nerve grafts. Recovery always occurred proximally to distally.

Discussion: Radial paralysis after femoral shaft fracture regresses spontaneously in 76% to 89% of the cases, depending on the series. There is a predominance in the 20 to 30 year age range. Several factors could be involved in radial paralysis (fracture of the distal third of the humerus, spiral fracture, plate fixation, nonunion). The anterolateral approach allows a better exposure of the nerve. Unlike other authors, we do no advocate exploration of the injured nerve during surgical treatment of the fracture because it is most difficult to determine the potential for recovery of a continuous nerve.

Conclusion: The risk of radial nerve paralysis is greatest for spiral fracture of the distal third of the humerus. In such cases, it may be useful to explore the nerve during the primary procedure and insert a plate. For other cases, we prefer to wait for spontaneous nerve recovery. If reinnervation is not observed at 100 days, we undertake exploration.

Purpose: Infection is a serious complication of total knee arthroplasty. Surgical strategies based on removal-reinsertion of the prosthesis in two times with antibiotic therapy has proven its efficacy. The use of a spacer between the two operations has been proposed to facilitate reimplantation. Since 1993, we have used this two-time procedure with an articulated spacer in an attempt to optimise functional outcome yet maintain anti-infection efficacy. We report our experience.

Material and methods: This retrospective series included 28 patients, 21 women (75%) and seven men (25%) who underwent surgery between December 1993 and February 2000.Mean age of the patients at revision was 67 years (18–83). Medical and surgical risk factors for infection were present in 64% and 54% of the cases respectively. Delay between prosthesis surgery and onset of the first signs of infection was 29 months (four days–222 months). A single-germ infection was involved in 18 cases (64%) and a multiple-germ infection in nine (36%). The infection was acute in 32% of the cases and chronic in 68%. There were eight fistulae (28%). Bacteriology reported staphylococcal infection in 25 cases (including 13 S. epidermidis), streptococcal infections in five, anaerobic germs in seven (corynebacterium in five) and Gram-negative germ (pseudomonas) in one. Delay between diagnosis of infection and insertion of the articulated spacer was 11 months (four days–62 months). The first operation consisted in removal of the prosthesis, wide excision of the synovial and infected tissues and insertion of the two articulated pieces, modelled with antibiotic-impregnated cement. Weight-bearing was authorised with crutches and an articulated brace. Rehabilitation exercises were performed to maintain joint amplitude. The prosthesis was reimplanted three months later (1.5–7 months). All prostheses were reimplanted with cement: two prostheses with posterior preservation, 20 posterior stabilised prostheses, and six hinge prostheses. The patients were given antibiotics for eleven months (1–25 months). The IKS score was used to assess functional outcome. Cure of infection was assessed on clinical, biological and radiographic findings.

Results: All patients were seen at a mean follow-up of 35 months (8–78). Follow-up was greater than 24 months in 68% of the patients. We had three cases (11%) of recurrent infection: one acute infection and two septic loosenings. At reimplantation, we had complications in seven patients (25%) ten of whom required revision surgery, six for mechanical complications (three dislocations, three aseptic loosenings). Mean IKS score was 136 points (50–190) with 79 points (30–100) for the knee and 67 points (20–90) for function. Mean flexion amplitude was 94° (45–115°).

Discussion, conclusion: With this method, joint mobility can be maintained between the two operations, greatly improving patient comfort. The mid-term results in terms of infection cure have been satisfactory (89% cure). Nevertheless, the final functional result can be disappointing, due to the persistence of pain (low-grade infection, difficult implant fixation…). The removal-reinsertion strategy using a single operation would in our opinion still have its indications.

Between 1997 and 2000, internal arthrodiastasis procedures (endo-apparatus), using an internal skeletal distraction device, were performed on 33 young patients who had reached the point of total hip arthroplasty or arthrodesis.

The mean age of the 20 males and 13 females was 19 years (range 11 to 51 years). We removed 19 implants, eight after completion of treatment or because they had outlived their usefulness, and 11 because no improvement in the hip disorder had been achieved.

Good results were achieved in two thirds of the patients, including patients suffering from avascular necrosis of the femoral head, old Perthes’ disease and contained hip dysplasia with joint space narrowing and pain. Chondrolysis and stiffness of the hip appear to be contraindications for this type of treatment. The three post-traumatic hip disorders were probably also not ideal cases.

In young patients, the results of total hip arthroplasty after trauma are poor, and the indications for internal arthrodiastasis should be redefined.

The effects of infection following implantation of an orthopaedic prosthesis are devastating. The prevention of perioperative contamination is therfore of the utmost importance in arthroplasty. We undertook a prospective study to assess bacterial contamination in elective arthroplasty surgery. Splash bowls containing sterile saline are used to store and clean instruments used during the course of a procedure. The incidence of bacterial proliferation in splash bowls was examined as a marker of intra-operative contamination. A 100mL aliquot of fluid was removed from the splash basin at the end of the procedure and passed through a grid membrane using a vacuum pump. The membrane filter was then plated on chocolate agar and colony counts recorded at 24 and 48 hours. Organisms were identified by standard techniques. Demographic data, and perioperative data including the duration and type of procedure, the number of scrubbed and other personnel in theatre and the type of skin preparation and gowns used were also noted. A total of 43 cases were examined. 14 samples yielded positive cultures. Staphylcoccus was the most commonly cultured organism (9 cases). Four patients grew Pseudomonas species. Five patients grew other Gram-negative organisms including Neisseria and bacillus subspecies. Five patients grew multiple organisms. Mean duration of follow up was 8.4 months (range 6 – 18 months). None of the patients with contaminated samples developed any clinical signs of infection in the perioperative period; nor was there clinical or radiological evidence of infection or loosening on subsequent follow up. Despite the use of a laminar airflow system in all cases, in excess of 30% of cases were contaminated. This study underlines the importance of adhering to rigorous protocol in theatre including minimising theatre traffic and the use of antibiotic prophylaxis.

We reviewed 351 cases of nonunion treated between 1987 and 2000. The principles of management included restoration of alignment, stabilisation and stimulation. More recently we used distraction and bone transport, bifocal techniques, single stage lengthening and correction of soft tissue contractures.

The ununited fractures resulted from trauma in 319 cases and in 32 were the sequelae of planned surgery. There were 159 atrophic, 89 hypertrophic and 103 infected nonunions. Nonunion occurred in the tibia in 162 patients, in the femur in 51 and in the upper limbs and other smaller bones in the rest.

At the time of this review, nine patients had abandoned treatment and 25 fractures remained ununited. Amputation had been performed on 20 patients, two at the request of patients with intractable pain, 14 following infection and four because of atrophy. Union was achieved in 297 cases (85%), including 90% of the atrophic, 89% of the hypertrophic and 73% of the infected nonunions. We found no statistically significant difference between the results of patients who smoked and non-smokers, but patients who smoked heavily healed more slowly.

Purpose: The anatomy of the endosteal canal of the proximal femur varies greatly in the general population. This variability can compromise total hip arthroplasty when a femoral stem is inserted without cement. While the secondary fixation of the implant is dependent on several parameters, the predominant factor is the primary stability and the large contact between the bone and the treatment surface of the apposed prosthesis. These two conditions, necessary but insufficient to guarantee an excellent clinical result, are obtained if there is a correct bone-implant morphology match. We analysed the morphology of the endosteal canal of the proximal femur to determine whether there is a standard anatomic conformation justifying the use of line prostheses.

Material and methods: We examined 30 femurs harvested from 30 individuals in a consecutive series in our anatomy laboratory. We made 12 scanner slices parallel to the knee joint line starting 1 cm above the apex of the lesser trochanter going up to 11 cm above the lesser trochanter. For each slice, we assimilated the canal to an ellipsoid surface to characterise its barycentre, the angle of the greater axis relative to the reference plane of the posterior condyles, and its dimensions defined with length (greater axis), and width (perpendicular to the greater axis).

Results: For each femur, the AP projections of the barycentres fell on a straight line (anatomic axis) and the lateral projections on a parabole. Helitorsion, i.e. the difference in the torsion angles between the first slice and the last slice was constant (57±8.5°). The dimensions were recorded for each slice.

Discussion: This method can be criticised. We were able to confirm the tridimensional data reported by Noble and confirmed the notion of a somatotype. We defined the normal (statistical) equation of the endosteal canal for the proximal end of the femur (barycentre, dimensions).

Conclusion: The anatomy of the endosteal canal of the upper extremity of the femur is not variable but standardised. It is thus possible to adapt the bone to the prosthesis.

Purpose: There is some controversy over the most appropriate management of knee dislocation. Following the 1995 SOFCOT symposium, the most promising results appeared to be obtained with emergency treatment using a synthetic reinforcement. The purpose of this prospective work was to validate this conclusion.

Material and methods: Between November 1994 and October 1998, 17 patients admitted for emergency care of a knee dislocation were included in this prospective study. Ten were men, mean age was 29 years (17–48). A complete work-up was acquired: plain radiographs with stress views, MRI in 14 patients. The central pivot was torn in all cases. Tears involved the lateral ligaments in eleven cases, the medial ligaments in six and the patellar tendon in one. There were no vessel lesions. One patient had popliteal sciatic nerve paralysis. Emergency surgery was performed to staple or suture the peripheral tissues and suture the posterior cruciate ligament plus a synthetic reinforcement (Ligastric); the anterior cruciate ligament was not repaired. Immediate rehabilitation started with mobilisation 0°/60°up to day 21 then with 0°/90° up to day 60. The lower limb was immobilised in an extension brace and weight-bearing was encouraged starting on day 60.

Results: All patients were reviewed at consultation with stress radiographs. Mean follow-up was three years (two to six years). The IKDC score was recorded. Four patients had arthrolysis, one had an isolated reconstruction of the anterior cruciate ligament, one had an ablation of the synthetic ligament and repair of the anterior cruciate ligament. The 70° posterior drawer was 18° preoperatively and 9 mm at last follow-up (21–0 mm). The greatest laxity corresponded to a patient who had had ablation of the synthetic ligament. The Pudda index was 6 mm, mean mobility was 0/130°, and two patients had asymmetric 10° recurvtum. Subjective outcome was very satisfactory for seven patients, satisfactory for nine and disappointing for one.

Conclusion: The objective result can still be improved by correcting the posterior laxity. Not repairing the anterior cruciate ligament immediately does not worsen prognosis. There were no complications related to the synthetic ligament. This therapeutic attitude can be proposed for major knee trauma.

We treated 133 traumatic posterior dislocations surgically between July 1994 and March 2001. In 16 patients, labral tears had occurred.

Operating on posterior hip dislocations, initially we fixated the posterior wall with screws and/or buttress plate, depending on the size of the fragment, and did suture the torn labrum, relying rather on the buttress plate or intact posterior wall for stability.

We began repairing the torn labrum when we realised that any small fragments still attached to the labrum simply pull out from under the buttress plate, allowing the hip to redislocate. Once the wall has been reconstructed, interrupted sutures are passed through the labrum, with the hip internally rotated to prevent shortening of the capsule when sutures are tied. A one-third tubular plate is placed over the sutures lying on the posterior wall and fixed with screws. The sutures are then tied individually over the plate. Postoperatively the patient is kept in bed for six weeks, with the hip abducted and knee extended.

Seven patients in whom the labrum was not repaired experienced redislocation. We performed second operations on two of them, repositioning the plates and reconstructing the posterior wall, but redislocation again occurred. The redislocated femoral heads were damaged because they rubbed against the plate and screws. In the other nine patients, we sutured the labrum, and in a 3 month to 2.5 year follow-up, no redislocation has occurred. .

Labral repair restores stability, and tying interrupted sutures over a buttress plate is an easy and effective method of repair.

We report a case of an aneurysmal cyst localized in the patella of a 37-year-old man. The lesion was secondary to a chondroblastoma at six years follow-up after initial curettage and bone graft. It were no recurrence. Treatment of aneurysmal cysts depends on the degree of articular involvement. We made a detailed study of 11 cases of this rare localization of aneurysmal cysts reported in the literature.

Tuberculosis of the spine is very common and it is important to do confirmatory testing.

This retrospective study involved 40 patients in whom tuberculosis of the spine was diagnosed after clinical examination and investigations. All underwent decompression of the spine for neurological fallout. Intra-operatively, histological tissue, MCS and polymerase chain reaction (PCR) were assessed. PCR was positive in only 50% of the patients, but was complementary to histology and MCS.

Purpose of the study: Proximal replantation is a technically feasible but life-threatening procedure. Indications must be restricted to patients in good condition with a good functional prognosis. The goal of replantation must be focused not only on reimplanting the amputated limb but also on achieving a good functional outcome. For the lower limb, simple terminalization remains the best choice in many cases. When a proximal amputation is not suitable for replantation, the main aim of the surgical procedure must be to reconstruct a stump long enough to permit fitting a prosthesis preserving the function of the adjacent joint. If the proximal stump beyond the last joint is very short, it may be possible to restore some length by partial replantation of spared tissues from the amputated part. We present here the results we obtained following this policy.

Materials and methods: This series included 16 cases of partial replantations, 14 involving the lower limb and 2 the upper limb. All were osteocutaneous microsurgical transfers. For the lower limb, all transfers recovered protective sensitivity following tibial nerve repair. The functional calcaeoplantar unit was used in 13 cases. The transfer of this specialized weight bearing tissue provided a stable distal surface making higher support unnecessary. In one case, we raised a 13-cm vascularized tibial segment covered with foot skin for additional length. For the upper limb, the osteocutaneous transfer, based on the radial artery, was not reinnervated, but this lack of sensitivity did not impair prosthesis fitting.

Results: One vascular failure was finally amputated. This was the only unsuccessful result. For all other patients, the surgical procedure facilitated prosthesis fitting and preserved the proximal joint function despite an initially very proximal amputation.

Discussion: The advantages of partial replantation are obvious compared with simple terminalization or secondary reconstruction. There is no secondary donor site and, because there is no major muscle mass in the distal fragment, the overall risk is very low compared with the risk of total proximal leg replantation.

Purpose of the study: Advances in chemotherapy protocols over the last 20 years have considerably improved the prognosis and functional outcome in patients with osteogenic sarcoma. We report here the results of a cooperative study conducted under the auspices of the French Society of Pediatric Oncology (SFOP). Twenty-nine oncology centers participated in this retrospective national multicentric study.

Materials and methods: The study included 15 .3 patients with osteogenic sarcoma of the limb who were treated by the OS87 protocol with conservative surgery between 1987 and 1994. The OS87 protocol consisted in conservative or nonconservative surgery combined with pre- and postoperative chemotherapy. The following inclusion criteria were used: age under 20 years, tumor localization in a limb (pelvis and spine excluded), no metastasis at diagnosis, biopsy proven osteogenic sarcoma.

Results: Mean age at diagnosis was 13 years. The knee localization predominated (80 p. 100). 82.5 p. 100 of the patients had grade IIB disease (Enneking classification). For the 187 patients included in the protocol surgery was nonconservative in 20 p. 100 of the cases and conservative in 80 p. 100. The choice of the surgical technique (arthroplasty, allograft, autograft, resection without reconstruction) depended on the patient’s age and school situation. Data analyzed here concerned only those patients who had conservative treatment. Mean follow-up was 64 months. The actuarial survival curve plateaued at 71 p. 100 at more than 6 years. Early and late complications were numerous and variable (mechanical, infectious, local recurrence). Secondary amputation was required in 10 p. 100 of the patients. The overall functional outcome of the preserved limbs was nevertheless good with rapid restoration of self-sufficiency despite major surgery and a high number of reoperations (about 65 p. 100 of cases).

Discussion: In light of the frequency and the seriousness of the complications, these results are modest. Patients and family should be advised of the risk, particularly the risk of secondary amputation which may be required early due to contaminated excision or at mid term due to major non-cancerological complications. As survival has been improved, functional capacity must be preserved for several years. This orients surgery towards more “biological” reconstruction which can provide greater longevity than arthroplasty.

Purpose: A fibrous element between the radial capitulum and the fovea is classically described; it is often called a synovial fringe. The term “meniscus” has been proposed to designate a truly rigid peripheral structure partially inter-postioned between the joint surfaces and susceptible of producing joint disease by internal disregulation of repeated pronation supination movements. This led us to study the anatomic and histological properties of this intra-articular structure.

Material and methods: Fifty adult cadaver shoulders were dissected. The en bloc resection included the capsule of the humeroradial joint and the entire annular ligament. We searched for a fibrous structure, noting its soft or rigid aspect, its position relative to the five-part segmentation of the capsuloligament resection, and its size and thickness. Vertical sections were made for the histology study to determine the organized connective tissue or synovial nature of the structure.

Results: An intra-articular element was visible in 43 cases, two structures were observed in two cases, on the deep aspect of the junction between the capsule and the annular ligament. The main positions observed were: circular (n=3), lateral and posterior (n = 11), posterior (n = 10). The anterior (n = 4), or lateral (n = 5) positions were rare. Mean length was 21.4 mm (9–51), mean width between the capsular attachment and the free edge was 2.9 mm (1–10), maxiam mean thickness was 1.7 mm (1–4 mm). The histology report showed two types of structures: a rigid structure with an oriented fibrous armature that had a triangular peripheral base continuous with the superior border of the annular ligament and covered with synovial on both sides of the free edge; a soft flexible structure formed uniquely by two layers of synovial and a more or less villous free edge. Fibrochondroid structures of the meniscal type were not observed. Small nerve fibers were demonstrated in some cases.

Discussion: Certain lateral epiconylalgias of the elbow would suggest involvement of the humeroradial joint, possibly related to injury of the humeoradial “mensiscus”. This study points out the frequency of this synovial or fiborsynovial fringe of variable dimensionts interpose between the radial capitulum and fovea. The structure has a more or less marked connective armature, basically in the lateral and posterior portion, and correctly cannot be termed a “meniscus”. This structure might be involved in inflammatory and painful syndromes observed in epicondylalgias of the humeroradial joint.

We present an original method for the treatment of neglected Monteggia fractures using the Ilizarov technique. This method allows reduction without accessing the radial head by progressive ulnar lengthening after proximal subperiosteal osteotomy of the ulnar bone. We used this method in a six and a half year old girl and achieved excellent radiographical and functional results with normal joint amplitudes. In our opinion, the quality of the outcome is related to the progressiveness of the bone lengthening enabled by this technique which allows restoration of the ulnar length, preservation of the axes of both forearm bones, and controlled reduction of the radial head.

Fundamental engineering considerations indicate that micro-movement of the components of any hip arthroplasty is inevitable: stress cannot exist without strain and vice versa. Micromovement can be classified either as inducible recoverable movement that takes place between the weight-bearing and non-weight-bearing phases of each stride, or as non-recoverable displacement between successive loading cycles.

Radiostereometric analysis is now sufficiently advanced to clarify migration and its significance, and is beginning to throw light on the extent and significance of recoverable cyclical micromovement. We discuss the value of radiostereometric analysis in identifying, early in their in-service life, implants that are likely to loosen.

Purpose: Arthroscopic reinsinsertion of rotator cuff tears is an alternative to surgical treatment, but there is some question as to the reliability of this technique. The purpose of this work was to assess healing with arthroscan, MRI or ultrasonography after arthroscopic reinsertion of the supraspinatus.

Material: There were 48 supraspinatus resections in 47 patients (27 men and 20 women), mean age 56 years (range 34–76 years). Thirty patients were active workers (109 manual labourers), seven were sedentary workers, and ten were retired. Mean initial Constant score was 40.56 (range 13–67). Arthroscan or MRI identified 48 full thickness tears of the supraspinatus (41 distal and seven intermediate tears, associated with twenty cleavages of the subspinatus, six cases of biceps tendonitis, and four lesions involving the upper third of the subscapularis.

Methods: All patients underwent totally arthroscopic reinsertion of the supraspinatus. One tenotomy of the long biceps and three reinsertions of the upper third of the subscapularis were also performed. All patients were immobilised for six weeks. Passive rehabilitation was started immediately and active work was allowed after six weeks.

Results: For this consecutive series of 48 supraspinatus reinsertions with a minimum 12 months follow-up, the Constant score at last follow-up was 76.77 (range 39–99). Arthroscan (n=40), ultrasonography (n=3) and MRI (n=1) were performed at six months to search for leakage and assess healing at the trochiter and cartilage level, aspect of the inferior aspect of the tendon and muscle degeneration. No leakage was observed in 37 cases, the tendon had a normal aspect in 15, with fringes in four cases, and in 12 cases there was a point leakage. Full thickness tear was found in seven cases. Clinical outcome was not correlated with operative technique or preoperative imaging.

Discussion: These results in a preliminary series suggest that arthroscopic reinsertion of suprasinatus tears with little retraction is a reliable alternative to surgical reinsertion. The deltoid insertions are not disrupted and adherence phenomena and morbidity are reduced. Arthroscopy also allows complete exploration of the glenohumeral joint. Longer follow-up will be needed to determine the long-term outcome.

Leakage after simple suture repair of rotator cuff tears depends on the overall preoperative fatty degeneration index (FDI) of the muscles and preoperative fatty degeneration (FD) of the infraspinatus. When the FDI is = 2, cuff leakage is always observed after repair. The risk of recurrent tears of the supraspinus is high if the FD of the infraspinatus is > 1. However if the FDI is very low or nil, the rate of recurrent tears is 15%. These tears can be explained by tension on sutures in macroscopically and histologically abnormal tendons.

Purpose: The purpose of this study was to determine whether repair of rotator cuff tears using sutures without tension after removal of abnormal tendon stumps, a technique requiring tendon plasty, can improve the leakage rate.

Material and methods: Total repair of 24 rotator cuff tears was performed without tension on the sutures after resection of at least one centimetre of the supraspinatus tendon stump. This consecutive series was studied prospectively. The tears involved the supraspinatus and the infraspinatus in ten cases, all three tendons in 13 cases and only the supraspinatus in one case. Mean preoperative FDI was 1.18 (0.5–2.16); pre-operative FD of the infraspinatus was a mean 1.19 (0–2). The supraspinatus stump was resected from the trochiter in 14 cases, on the apex of the head of the humerus in seven and facing the glenoid cavity in three. Repair required translation advancement of the supraspinatus in 24 cases, translation advancement of the infraspinatus in six (associated with a rhomboid flap) and a trapezeal flap in three cases. Postoperative leakage was assessed with arthroscan (n=23) and ultrasonography (n=1) at one year.

Results: No leakage was observed in 20 of the 24 cuffs (83%). Recurrent tear of the supraspinatus was observed in three cases and in the supraspinatus and infraspinatus in one case each. The FDI of cuffs with recurrent tears (1.31) was not significantly greater than the FDI of cuffs without leakage (1.15) (p = 0.085). Preoperative FD of the infraspinatus of cuffs with recurrent tears (1.5) was significantly higher than that for cuffs without leakage (1.12) (p = 0.16). For the supraspinatus and the subscapularis, there was no significant difference between preoperative fatty degeneration of cuffs with recurrent tears and cuffs without leakage. The number of repaired tendons had a statistically significant effect (p = 0.012) on postoperative leakage: 23% of the recurrent tears after repair of three tendons showed no leakage compared with 9% after repair of one or two tendons (there was no significant difference for preoperative FDI, p = 0.33).

Discussion: Resection of macroscopically abnormal tendon stumps which requires tendinomuscular plasty, gives better anatomic results than simple suture. For an equivalent FDI, this allows fewer cases of leakage (83% without leakage compared with 50% after simple suture). Results were also better for an equivalent number of tendons repaired: 77% and 50% for three tendons and 91% and 55% for two tendons respectively).

Conclusion: Despite the almost constant need for plasty, rotator cuff repair using sutures without tension after resection of macroscopically abnormal tendon stumps gives, for an equivalent preoperative degree of fatty degeneration and an equivalent number of tendon repairs, better anatomic results than simple suture.

Purpose: There are three main causes of failure after valgisation osteotomy of the tibia requiring repeated osteotomies: insufficient valgus, excessive valgus, or loss of the valisation correction after a variable delay. The purpose of this study was to evaluate outcome after repeated oseotomies performed in relatively young patients or too active to propose arthroplasty. The technical problems were different for each aetiology.

Material and methods: The series included 47 knees operated on between 1974 and 1998 after a first osteotomy performed at a mean age of 46 years. Mean delay between the two operations was five years (1 to 12). A medial closure osteotomy had been performed at the first operation in 34 cases and a lateral opening osteotomy in 13. For the 19 knees with valgus, the second osteotomy was a medial closure in 14 and a lateral opening in five. A repeat valgisation was performed in 28 cases, 18 by lateral closure, one by medial opening and nine by curviplanar osteotomy. The IKS score was determined to assess function. The femoraotibial axes (HKA angle) were determined on full stance views. The Ahl-back osteoarthritis grading was used. For 17 patients who had undergone operations in other institutions, exact measurements were not always available concerning the preoperative status and the initial correction.

Results: The overall IKS score for function improved in 87% of the cases with a mean follow-up of five years. The IKS knee score improved from 73 to 89 points and the IKS function score from 65 to 81 points. For the 19 over-corrections, the mean HKA angle was changed from 190° to 184°. For the 28 under-corrections, the mean HKA angle was changed from 173° to 182°. The tibial tilt remained unchanged at 7° as did lateral gapping at 3°. Delay to consolidation was a mean 96 days.

Discussion: Revision osteotomies performed for correction defects should be distinguished. For these procedures, it would be logical to expect a good result if a 3 to 5 degree valgus is achieved. Revisions after a long period (33 cases) are different; required for wear, these cases correspond to progressive loss of the initial osteotomy effect. These patients are often candidates for prosthesis if seen after 70 years. Good results can however be obtained with a second osteotomy irrespective of the initial technique. We prefer reoperating with medial opening after initial lateral closure.

This paper reviews the causes of chronic instability after total hip arthroplasty (THA).

The overall reported incidence varies from 0.5% to 9.5%. At 2% to 6%, the incidence following primary THA is higher with a posterior approach than with an anterior approach (0.5% to 3%). The incidence is reported to be as high as 22% after revision THA and 50% after extensile triradiate approach for pelvic discontinuity.

Inadequate soft tissue lengthening, damaged abductors and nonunion of trochanteric osteotomy are known to predispose patients to chronic instability after THA. Elderly women are particularly susceptible. Poor patient compliance is also a cause.

Surgical technique is also a factor. The lateral decubitus position often causes flattening of the lumbar lordosis, leading to potential cup retroversion. Over 90% of all dislocations are posterior, and disruption of external rotators and capsular damage should be repaired if possible. The optimal implant position appears to be 40° TO 45° of abduction, 15° to 20° of femoral anteversion, and 20° to 30° of cup flexion. Elevation of the hip centre weakens abductor pull, causing instability. Because a reduced femoral offset causes potential instability, this should be measured preoperatively to make sure that the stem can provide adequate offset. It may be necessary to add a thicker liner to increase the offset.

Prosthetic factors which play a role in chronic instability include the use of smaller femoral heads, thick necked stems and heads with skirts. A larger femoral head increases stability simply by increasing the radian about the hip centre, increasing the potential range of motion. Extended posterior wall-adds improve the range of motion, and consequently the stability. However, there are fears that their use may increase the incidence of impingement and/or lead to increased wear. Skirted femoral heads impinge on the liner, limiting movement, and their use should be avoided in most cases of instability.

Femoral stem offset relates to the neck shaft angle and the effective hip centre/shaft axis length or offset. It is easier to increase offset with lower neck shaft angle than to lengthen the leg. Because a bell curve is used in the design of femoral stems, many prosthetic systems lack adequate offset, especially when larger stems (48 mm to 52 mm) are used.

In earlier prosthetic designs, bulk was added to the necks to eliminate stem breakage. In certain stems, the way in which dimensions were scaled meant the neck dimensions of larger prostheses were disproportionately big. We stopped using Depuy Stability stems sizes 16 mm and 18 mm because of this. Thornberry et al have shown that a circulotrapezoidal neck design is the best shape and leads to the least impingement. They have also shown that increasing the width of the chamfer of the acetabular liner rim improves the range of motion.

In treating early instability (occurring less than 30 days postoperatively) most authors recommend bracing for six to eight weeks and warning patients severely about the long-term potential of redislocation. In cases of chronic instability (occurring more than 30 days postoperatively) all potential problems must be explored: these include soft tissue laxity, cup retroversion, inadequate offset, surgical approach, etc. In managing multiple dislocation, the use of extended immobilisation is less desirable although patients who have undergone revision have been subjected to a great deal of soft tissue dissection and potentially should be braced for up to 12 months. If the cause is correctable-malpositioning, soft tissue laxity or bony impingement – treatment is likely to be successful in 85% of cases. However, if the implants are in good position, the ‘bloodless revision’ (Fehring) has less than 50% chance of succeeding. The implication is that an extended posterior wall liner, longer modular femoral head, and soft tissue reconstruction are not going to work in the majority of cases.

Designed by Noiles, the J& J SROM constrained acetabular liner uses a polyethylene capture mechanism that is secured by two additional screws. The pullout strength of this device is 1 350 N but torque required (lever-out strength) diminishes to 17.3 N.m for a 28-mm head. With a 32 mm head, 105° of flexion was obtained (while the normal hip needs up to 113° for usual flexion). Following up 21 patients with this implant for over two years, Anderson et al found redislocation in 29%. The only causative factor identified was an abduction angle of more than 70°. However, there were no cases of implant loosening of this device. Prevention of loosening was one of the design goals in using a ‘softer’ locking mechanism. Dislodgement of the liner requires immediate re-operation.

The Osteonics constrained liner cup has a dual socket. The inner socket has a polished chrome surface manufactured fit to the outer socket. It fits a 22 mm or 28 mm head, and has a locking ring identical to the bipolar implant that holds the head in place. The implant can be snap-fitted into a 52-mm or larger Osteonics cup. This liner can also be cemented into another metal-backed liner. Goetz et al evaluated 56 cases, in 10 of which this implant had been cemented and in 46 lock-fitted in appropriately matched metal shells. In one case, the cemented constrained liner had separated from the metal shell. None of the constrained liners had separated from the metal shells, but one shell had loosened.

There are many similar constrained acetabular liners. The choice is between a ‘locked’ liner that can never separate and a ‘softer’ lock that may protect fixation of the cup.

Hypertrophy of lumbar articular facets and dorsal joint capsule are well documented in degenerative instability, the molecular changes occurring in the extracellular matrix (ECM) are however unknown.

The L4/L5 posterior articular complex was removed from seven individuals undergoing fusion for degenerative instability. After methanol fixation and decalcification in EDTA, specimens were cryosectioned at 12 μm and immunolabelled with monoclonal antibodies for collagen types I, II, III, V and VI; chondroitin-4 and 6 sulphates; dermatan and keratan sulphate; versican, tenascin, aggrecan and link-protein. Antibody binding was detected using the Vectastain ABC ‘Elite’ kit. Labelling patterns were compared to corresponding healthy specimens examined previously.

In comparison, the degenerative capsule was more dense and hypertrophied and the enthesis more fibrocartilaginous, with immunolabelling extensive for collagen type II, chondroitin–6-sulfate, chondroitin-4-sulfate, aggrecan and link-protein. The articular surface showed extensive evidence of degeneration, while the thickened capsular entheses encircled the articular facets dorsally. Bony spurs capped with regions of cartilaginous metaplasia were prominent in this region, the ECM labelling strongly for type II collagen and chondroitin-6-sulfate.

The hypertrophy of lumbar facet joints subject to instability of the functional spinal unit therefore appears to be due to proliferation of the capsular enthesis rather than the actual articular facet. In view of the physiological function of the dorsal joint capsule as a wrap-around ligament in assisting the limitation of axial rotation, the molecular changes found in degenerative instability suggest rotational instability, such as results from degenerative disc disease, to be a decisive factor in the development of spondylarthropathy. It is furthermore probable, that the pronounced sagittal joint orientation in degenerative instability is the result of reactive joint changes rather than a predisposing factor of instability.

Purpose: Dislocation of total hip arthoplasties is a sad reality. The incidence of this complication is estimated from 0.6 to 8%. Dislocation can be a single event that never recurs, but half of all dislocations will reoccur again. We analysed outcome after treating chronically unstable total hip arthroplasties using a double-mobility cup.

Material and methods: Between 1990 and 2000, we treated 42 cases of recurrent dislocation of total hip arthroplasties. Five were immediate, 33 early, and four late; five dislocations on the average. The prosthesis was implanted via the posterolateral approach for 36 patients. Thirteen patients treated in our unit had already had surgical treatment for chronic instability: 1 trochanteoplasty, 8 bone blocks, 5 restraining cups. A standing AP view of the pelvis was obtained in all patients before surgery to analyse shortening (gluteus medius insufficiency), cup tilt and anteversion, and stem lateralisation. Likewise a CT scan was performed systematically to analyse stem and cup anteversion. No position anomaly was found in 17 patients; at least one anomaly was found in the others. All patients were reoperated via the posterolateral approach. A double-mobility cup was implanted systematically without changing the stem.

Results: Among the 42 patients, we had two with recurrent dislocation, one in a neurologic patient and one in a patient with major anomalies in the position of the femoral component that was not changed. The incidence of recurrent dislocation was thus 4.75%.

Discussion: The therapeutic method used here can be compared with other solutions (trochanteroplasty, anti-dislocation crescent, antidislocation bone block, bipolar replacement). The double-mobility cup is particularly interesting for high-risk patients: neck fracture, tumour surgery, neurological disease, antecedent non-prosthetic surgery (dearthrodesis prosthesis). We advocate revision surgery after three dislocations.

Conclusion: The double-mobility cup appears to be a valid therapeutic option, both for the treatment and prevention of chronic instability of total hip arthroplasty.

Purpose: Arthroscopic arthroplasty for painful shoulder is not always successful. Repeated arthroscopy is sometimes discussed for patients with recurrent pain. The purpose of this work was to determine the technique and identify indications.

Material and methods: We conducted a retrospective analysis of 24 patients (13 men, 11 women), mean age 52 years, who underwent repeated arthroscopy after failure within 31 months of arthroscopic acromioplasty with no other intervention. Three groups were formed: group 1 (7 patients): subacromial impingement due to tendinitis with intact supraspinatus; group 2 (11 patients): subacromial impingement secondary to cuff tear; group 3 (6 patients): calcified tendinopathy. In group 1, the acromion was type 1 in three cases, type 2 in three and type 3 in one; repeated arthroscopy included complementary acromioplasty. In group 2, all patients had complementary acromioplasty; six of them with biceps tenotomy. In group 3, the remaining calcification was removed in all patients and complementary acromioplasty in three.

Results: Mean follow-up was 21 months. In group 1, outcome was satisfactory in three patients (43%), irrespective of the acromial morphology. In group 2, outcome was satisfactory in six patients (55%), including five with acromioplasty with tenotomy and only one with complementary acromioplasty alone. In group 3, outcome was satisfactory in five patients (83%); one failure was attributed to remaining calcification; acromioplasty did not influence outcome.

Discussion, conclusion: The acromion should not be considered as the principal cause of failure after first acromioplasty. In this series, only 33% of the patients who had complementary acromioplasty had a good outcome at last follow-up. Biceps tenotomy in patients with rotator cuff tears and removal of the calcium deposit in patients with calcified tenopathies should be considered first.

Purpose of the study: The principal objective of this prospective continuous observation study was to determine the incidence of perioperative and early postoperative complications secondary to surgical treatment of lumbar stenosis. Secondary objectives were to describe these complications and try to identify favouring factors.

Material and methods: All patients without major spinal deviation who underwent surgery for lumbar spine stenosis in our unit from January 1998 to January 2000 were included in the study. Minimal follow-up had to be six months. The series thus included 306 patients. Three categories of preoperative parameters were recorded: comorbid fractures, type of stenosis operated, type of surgery (simple release, release plus fusion, etc). In order to obtain an exhaustive data set, all complications were recorded on observation charts during hospitalisation and at follow-up visits at three, six and twelve months postoperatively. Complications were divided into four major categories: major complications, early or late infections, early or late mechanical disorders, neurological complications including meningeal disease and neurological disorders secondary to surgery. Data were explored with univariate analysis to determine the overall incidence of complications and the specific incidence for each category of complications and multivariate analysis with logistic regression to determine factor favouring development of complications.

Results: Overall incidence of complications secondary to surgery was 26.5%. Incidence of general, infectious, neurological and mechanical complications were 13, 4.5, 2.6, and 2% respectively. Incidence of complications considered to be serious and/or requiring reoperation was 12%. Factors influencing the development of complications were comorbidity, body mass index, duration of the operation, and reoperation.

Discussion and conclusion: The rate of complications reported in the literature have been very variable and have been established from retrospective reviews making comparison with our findings rather difficult. Our work pointed out the role of certain favouring factors which could be usefully examined in a larger series.

Purpose of the study: Surgery for lumbar canal stenosis is classically an intracanalar procedure with the risk of injury of the dura mater or nerve roots or of postoperative haematoma with secondary sequelae. Extracanalar surgery could be useful for the treatment of lumbar canal stenosis in older patients.

Material and methods: The Farcy procedure is based on the observation that the root is compressed in the recessus by the tip of the upper facet. The foramen is too small. The tip can be cut with a chisel along a horizontal line plumb with the pedicle landmark on the upper border of the lateral mass. The tip of the facet and its osteophyte can be removed laterally to medially with a curette and separated from the capsule and the yellow ligament without exposing the root. Release of the foramen is verified with an elevator. From August 1999 to July 2000, 15 patients (ten women and five men) underwent the Farcy procedure in association with fusion-osteosynthesis. Mean age was 60.4 years (55–71). The patients had suffered a mean 8.5 years (1–30). All had lumbalgia. Radiculalgia involved one root in seven patients, two in four and three in four. The Beaujon score was 6.73 (0–14) before surgery. The procedure was performed at one level in five patients, at two in four, at three in four and at four in two. Laminectomy was associated in two patients early in our experience.

Results: Postoperative Beaujon score was 15.2 (9–12) with cure of lumbalgia in eleven patients and cure of radiculalgia in ten patients. five patients had a 100% relative gain and only four had a gain of less than 50%. There were two failures explained by a history of stroke in two women (67 and 71 years). The only complications were one haematoma that was reoperated and one superficial infection.

Discussion: These results are comparable with those obtained with intracanalar surgery. The procedure is equally effective and is more rapid without the risk of the classical complications. The one extradural haematoma observed was related to laminectomy which later was noted to be unnecessary.

Conclusion: The Farcy procedure is a useful technique for the treatment of lumbar spine stenosis. Further experience is needed to determine whether this extracanalar technique should replace classical techniques with the risk of complications related to exposure of the canal.

Total knee arthroplasty (TKA) is done primarily for pain relief, and function improves when there is less pain. Greater understanding of the biomechanical functioning of the knee has led to an improvement in prosthetic implants. Surgical technique, which plays an important role in the overall outcome of TKA, has also improved over the years. Simultaneous bilateral total knee arthroplasty (SBTKA) is one of the latest techniques employed by arthroplasty surgeons. SBTKA has advantages and disadvantages, and there are clearly diverse reactions to it from surgeons treating patients with bilateral osteoarthritis.

We reviewed 87 patients who underwent SBTKA and compared complications, costs and functional results with those of patients who underwent staged TKA. The same surgeon performed all the operations. There was strict adherence to a consistent preoperative, intraoperative and postoperative protocol.

Our results showed that the complications of SBTKA are not significantly different from of staged TKA. SBTKA is definitely more cost-effective, and rehabilitation and function were the same as in patients who had a staged procedure.

Purpose: Desmoid tumours are uncommon in the axillary region. We report the clinical course in seven patients operated for desmoid tumours of the axillary region.

Material and methods: Our series included two women and five men. Mean age was 52 years (39–60). One tumour was in the trapesium, two were in the retroplexic, two in the axillary fossa, one in the deltoid and one in the upper part of the arm. Biopsy and magnetic resonance imaging were obtained in all patients. Surgical margins were in healthy tissue in five cases; resection was limited to intratumoural tissue in one. The axillary nerve had to be sacrificed in two patients, the spinal nerve in one and the medial nerve in one. Chemotherapy was given to one patient prior to surgery.

Results: Mean follow-up was 51 months (23.2–162.1). Five patients experienced at least one relapse requiring one or two complementary procedures. Among the relapse cases, one patient required resection of the median nerve with bypass of the humeral artery. No amputations were necessary and the brachial plexus was not sacrificed. Four patients were given one to five adjuvant chemotherapy courses. Two were given radiotherapy. Shoulder motion was preserved in two patients, moderately reduced in five. Elbow and finger mobility was compromised due to the medial epicondylar site of the tumour in one patient whose median nerve had to be sacrificed.

Discussion: Even though the surgical margins were in healthy tissue, the risk of relapse was high in our patients as in other series reported in the literature. The course does however stabilise after several episodes of recurrence, an observation reported in the literature and confirmed in our patients. In case of brachial plexus involvement, several authors advocate preservation of upper limb function despite incomplete tumour resection, proposing postoperative radiotherapy.

Conclusion: Desmoid tumours of the axillary region seriously compromise upper limb function. Surgical resection should be as complete as possible but without sacrificing upper limb function.

Sciwora lesions are common in children but rare in adults. In adults, they are often associated with spondylosis, and minor trauma may result in paralysis of varying degrees.

In our unit we conducted a retrospective analysis of adult patients with spinal cord injuries. Only two had Sciwora lesions. One lesion was in the thoracic spine and the other in the lumbar spine. The thoracic lesion led to complete paraplegia, with intrinsic cord damage. It was treated conservatively and the patient did not recover. The lumbar lesion was incomplete, with traumatic disc prolapse that recovered after discectomy.

Management of Sciwora lesions of the thoracic and lumbar spine depends on MRI findings.

We evaluated the effectiveness of arthroscopic repair in patients with shoulder instability owing to a bony fragment as part of the Bankart lesion, using spiked Suretacs, sutures and anchors.

Over a two-year period, we followed up 23 of 25 consecutive cases, all with a bony fragment as part of the Bankart lesion. The mean age of patients, all of whom were male, was 21 years (17 to 35). Almost all injuries were sustained playing sports. Patients were clinically evaluated at six weeks and 20 weeks postoperatively and interviewed telephonically.

Full arthroscopic examination was performed in a lateral decubitus position. The affected capsular structures and labrum, with its attached bony fragment, were fully mobilised. The bony fragment was always attached to the capsular structures, with labral ring intact. We used a spiked Suretac anchor to reattach the bony fragment to its original anatomical position, and Mitek anchors and no. 1 Ticron sutures for individual reattachment of the capsule and ligaments. Postoperatively patients were immobilised in a shoulder sling for six weeks. Early restricted active and passive movements were advised. Patients routinely received postoperative physical and biokinetic rehabilitation. The mean follow up period was 16 months (5 to 29). There was no redislocation or subjective instability.

This technique yields excellent results, but because it is technically difficult should be used only by experienced shoulder arthroscopists with thorough knowledge of pathological shoulder anatomy.

A nine-year-old girl presented with a four-year history of progressive bowing of the left tibia. She had been seen in our clinic three and four years earlier, when no treatment was advised. She had been complaining of mild pain in the left leg for one month but was otherwise not very perturbed about her deformed leg.

Examination showed bowing of the left tibia, no leg length discrepancy, no limp, and a normal left knee and ankle. Radiological examination showed features of osteo-fibrous dysplasia of the left tibia, with eccentric expansion of the cortex, intracortical osteolysis, marginal sclerosis encroaching on the medulla and diffuse lesional calcification. No other bones were involved.

Because of the progressive bowing of the tibia and the mild pain, the recommended loose observation of the patient was abandoned. Daily treatment with 30 mg IVI pamidronate for three days resolved the pain. One month after the latest presentation the lesion was biopsied. Histological examination confirmed the diagnosis of osteofibrous dysplasia of the tibia. There was no evidence of adamantinoma.

The literature on this rare bone lesion in childhood supports the use of open biopsy if the deformity becomes painful, the bowing is progressive and the patient presents after the age of nine years. Important differential diagnoses include fibrous dysplasia and adamantinoma.

The treatment of large bony defects following osteomyelitis and trauma with skin damage is challenging. This paper reports the results of fibular transplant for tibial defects.

Between 1990 and 2000, five children aged four to nine years were treated. Four had pyogenic osteomyelitis and one a compound fracture with bone loss. All had large wounds on the medial aspect of the tibia. Before reconstruction, conservative treatment lasted five to six months. Sequestrectomy and debridement were performed before fibular transfer.

At surgery the fibula was divided below the physis and transferred to the remaining tibia, deep to the tibialis anterior muscle belly. In two cases the fibula was fixed to the lateral aspect of the tibia with screws, and in three into the metaphysis with K-wires. Bone graft was packed around the transfer. Immobilised in a cast for four to six months, the leg was later protected with a calliper.

Follow-up ranged from 9 months to 10 years. All children are ambulant, four with callipers and one independently. The latter shows evidence of tibialisation of the fibula. Follow-up continues and the remaining four transfers show solid union and signs of fibular hypertrophy.

Osteomyelitis remains a crippling condition that results in bone defects. Fibular transfer is a salvage procedure and an alternative to ablation in cases of severe bone loss with infection and scarring. It should be reserved for difficult cases with extensive defects where conventional bone grafting is not possible.

At the same time as the LCS knee, the ARD knee was developed. We aimed to assess whether over a 10 to 15-year period the SS 86 rotational platform knee system stood the test of time.

In a retrospective study, we followed up 250 patient, assessing patient satisfaction, range of motion and radiological appearance. Patient satisfaction was high and range of motion and radiological appearances very good.

We discuss aspects of glenohumeral instability and rotator cuff tears in a clinically orientated approach, presenting a new way of quantifying structural bone loss from the anterior glenoid and defining the Glenoid Index as an indicator of the appropriate surgical approach to address anterior instability.

Repair of the rotator cuff depends on viable and functional muscular tissue. We discuss the potential for repair of the supraspinatus tendon in relation to the tangent sign, fat infiltration and retraction. Comparing MRI and arthroscopic findings, we highlight pitfalls in the diagnosis and repair of the subscapularis tendon.

Between January 1990 and October 2000, 108 total hip arthroplasties using a cemented polished titanium stem and a cemented ultra-high molecular weight polyethylene (UHMWP) cup were performed at our hospital. Because during routine follow-up visits we noted instances of resorption of the calcar, we decided to assess whether this was a problem. We were able to assess 85 of the original 108 hips.

Calcar resorption was observed in 43 hips. The extent of calcar resorption varied from 1 mm to over 15 mm. In one patient a biopsy showed typical polyethylene granuloma.

Because there is a risk of long-term failure, we concluded that it is inadvisable to use a cemented polished titanium stem when UHMWP is one of the bearing surfaces.

Painful conditions of the acromioclavicular (AC) joint are common in South Africa, particularly among sportsmen. These conditions are often treated by open excision of the distal end of the clavicle, but an arthroscopic procedure offers many advantages.

From February 1994 to February 2000, we performed 138 procedures. The mean age of patients ({71% men and 29% women) was 29 years (19 to 53). In cases of rotator cuff impingement, arthroscopic acromioplasty was followed by clavicular excision via the subacromial route. With a normal acromion and rotator cuff the AC joint was approached through two superior AC portals, avoiding removal of the AC ligaments. In all cases a standard 3.5-mm arthroscope was placed in one portal for viewing and the mechanical shaver inserted through the other. About 7 mm to 8mm of bone was removed from the clavicle. Patients were in hospital for about a day and 87% were discharged the same day.

The mean follow-up time was 34 months (2 months to 4 years). Patient satisfaction was high in 32%, fair in 60% and poor in 8%. Most patients (92%) returned to all previous sports and activities.

We concluded that the arthroscopic Mumford procedure is at least as successful as its open equivalent. It can be done as an outpatient procedure and permits a rapid return to activities. Cosmesis is excellent and stability of the AC joint is preserved.

The rotator cuff is sited on the anatomical neck of the humerus and is formed by the insertion of the supraspinatus (SP), infraspinatus (IS), teres minor (TM) and subscapularis. All play a vital role in the movement of the glenohumeral joint, and the anatomy is of critical importance in arthroscopic rotator cuff repair. We undertook an osteological and gross anatomical dissection study of the insertion mechanism of these tendons, in particular the SP .

The SP inserts by a triple or quadruple mechanism. The ‘heel’ (medial) and capsule fuse, inserting into the anatomical neck proximal to the anterior facet of the greater humeral tubercle. The ‘foot arch’ inserts as a strong, flat, fibrous tendon into the facet. This area is cuboidal, rectangular, or ellipsoid, and measures 36 mm² to 64 mm². In about 5%, the insertion is fleshy (pitted), rendering it weaker than a tendinous attachment. The ‘toe’ lips over the edge of the facet laterally and fuses with the periosteum, fibres of the inter-transverse ligament and the IS. A proximal ‘hood’ of about 4 mm stretches down inferiorly and fuses with the periosteum of the humeral shaft. The subacromial or subdeltoid synovial bursa are sited laterally.

The IS and TM insert into the middle and posterior facets (225 mm and 36 mm²) at respective angles of 80° and 115°. The inferior portion of the TM facet is not fused with the shoulder capsule. The subscapularis inserts broadly into the lesser tubercle, and the superior fibres fuse with the shoulder capsule and intertransverse ligament. The insertion of the subscapularis does not contribute directly to the formation of the ‘hood’, which belongs exclusively to the SP, IP and TM.

This study confirms the complexity of the SP insertion and suggests that an unfavourable attachment or biomechanical anatomical malalignment may lead to eventual tendon/cuff degeneration.

Calcium sulphate is now a proven adjunct to the replenishment of bone stock in joint replacement surgery. Alone and as a composite, it has been used successfully for many years in both dental and orthopaedic applications. OsteoSet (Wright Medical Technology), a processed, purified material, has been used as a bone void filler in 51 revision total hip arthroplasty (THA) procedures.

Follow-up of these cases ranges from 3 to 48 months. Radiographs show that the calcium sulphate has disappeared in all cases. In all but three patients, all of whom had failure of the acetabular component or infection, the calcium sulphate has been replaced with what appears to be trabeculated cancellous bone. Clinical results for cases that did not have mechanical failure or infection are indistinguishable from any revision THA in which the acetabular component is well fixed.

Implantation of the calcium sulphate pellets calls for preparation of a well vascularised bed. The pellets are placed in such a way that load is not transferred to them from the implanted acetabular component. Rather, the load should be transferred from the acetabular component directly to host bone. Postoperatively, load bearing is limited for at least eight weeks and for longer of the quality of the supporting bone is poor.

Periprosthetic fractures may occur intraoperatively or postoperatively. The incidence of is approximately 0.6% in primary and 2.4% in revision total hip arthroplasty. Predisposing factors include stress risers, osteolysis, osteopoenia, singly or in combination. Focusing on postoperative fractures, this paper provides a management algorithm.

If the fracture is stable, conservative treatment is appropriate. If the fracture is not stable, one needs to determine whether the prosthesis is loose or not. If the prosthesis is loose, further management will depend on the quality of the bone stock. Good bone stock will allow revision with a long stem or impaction grafting, while poor bone stock will require extensive allografting. Similarly, the adequacy of the bone stock determines the management regime if the pros-thesis is not loose. In the presence of good bone stock, it is usually possible to carry out open reduction and internal fixation. Poor bone stock requires bicortical onlay allografting.

From 1994 to 1998 36 periprosthetic fractures, 14 with stable implants and 22 with unstable, were treated. The stable implants were treated with Dall Miles plates, fixed with cables and crimp-sleeves, bicortical screws distal to the fracture and unicortical screws proximally. The fracture united in 11 hips, two of which subsequently required prosthetic revision for femoral loosening. In one hip the fixation failed with fracture of the cables. Despite other adverse reports, this type of system is recommended for fixation of periprosthetic fractures where the prosthesis is stable.

The 22 periprosthetic fractures with unstable implants were treated using the Bicontact long stem revision implant. Two distal interlocking screws provided early rotational and axial stability, and 14 patients had additional allografting.

Radiological evidence of fracture healing was apparent in all cases. One prosthesis subsided by more than 5 mm with fracture of the interlocking screws. Cementless long stem revision is the treatment of choice for periprosthetic fractures associated with a loose implant.

To ensure successful outcome it is necessary to determine the extent of the fracture, to assess fracture stability and to appreciate the available and appropriate treatment options. It is necessary to ‘be prepared’: these are challenging problems and the final decision often hinges on intraoperative findings.

Supracondylar femoral fractures challenge even the most experienced trauma surgeon. Fracture comminution often extends into the articular surface, increasing the risk of joint stiffness and post-traumatic arthritis. This is a preliminary prospective report of 42 supracondylar femoral nailing procedures performed on 41 patients between July 2000 and March 2001.

The mean age of the 21 women and 20 men was 62 years. Five fractures were compound. Classified according to AO classification, there were 28 type-AIII fractures, 10 type-AII, two type-CIII and two type-CII. In all cases a percutaneous surgical technique was used and a 13-mm x 250-mm supracondylar nail inserted. The mean operative time was 70 minutes. Mean follow-up was four months (2 to 10). There were no deep or superficial infections and no implant failures. Twenty fractures healed with no shortening within four months. The mean flexion arc was 105° (5° to 130°). Eight patients with osteoporosis had 1 cm to 2 cm of shortening, which did not affect functional outcome. Of the 20 patients whose fractures united, 17 had no pain and three had mild anterior knee pain. A single patient had 8° of valgus angulation at the fracture site.

This study shows that supracondylar femoral nailing provides improved fracture stabilisation both in elderly patients with osteoporotic metaphyseal bone and in younger patients with extensively comminuted fractures. Percutaneous techniques eliminate the need for extensive surgical dissection, shorten operation times and reduce blood loss.

There is great confusion in the literature on mechano-transduction in osteoblasts. This is partly due to the use of hyper and hypophysiological systems for applying forces to cells. We only find evidence for the role of ion channels at hyper-physiological levels of strain. The cells are far more sensitive to tension than compression indicating that structures within the cell are decisive in determining response and that there is no tensegrity within the cell. Single cell mechanical measurements using an adapted atomic force microscope built in our lab, also does not show any evidence for a tensegrity structure. Analysis of the dimension of stretch and the amount of force needed to activate cells indicates that stretch activated ion channels are not involved as the force required is extremely high in relation to the activation energy of an ion channel. The force required to activate at the mechanosensing system is more in line with the forces generated inside a cell by the actin-myosin structure of several hundred thousand piconewtons.

We find no evidence for any other pathway than a PLC-PKC-Calcium pathway involved in any of the signal transduction pathways, but other pathways are involved in hyperphysiological stretch. One of these induces ICAM-1 and thus can induce inflammatory pathways through cell-cell binding of macrophages and other cells.

Due to the very high energies involved in activating the mechano-transduction pathways we do not see any graviception mechanism of single cells. Indeed many microgravitx flights of 25 seconds duration and a flight of 6 minutes did not show any effect in intracellular calcium. The cellular response to microgravity, if it is not an artefact, is not related to mechanosensing.

This work was supported by the German Space Agency (DLR)

In the past, many high tibial osteotomies were done to relieve symptoms of osteoarthritis. These osteotomies have largely been replaced by total knee arthroplasty (TKA).

This paper presents the long-term results of 270 osteotomies followed up for 10 years and discusses the complications involved in subsequent conversion to TKA.

Using the trabecular bone bioreactor (ZETOS) developed in our laboratories we have investigated the formation of bone using the fluorescent bone seeking markers calcein and alizarin red. And the association of bone formation with the increase in stiffness with mechanical loading.

10 mm diameter bone cores 5 mm thick were obtained from the distal radius /ulna of cows obtained at the slaughter house. by precision cutting with diamond saws and keyhole cutters (our pattern) in sterile 7–10°C phosphate buffered saline (PBS) and cultured in a variation of DMEM containing fructose HI GEM.

Results: Loading the bone 30x 4,000μ per day resulted in an increase of stiffness of 35%, by day 30 while the non loaded controls decreased in stiffness. Calcein was added at day 27 to the circulating medium for 4 hours and then fresh medium was circulated. On day 30 alazarin red was circulated through the trabecular bone. The bones were subsequently fixed and embedded in resin and sectioned by classical histological techniques. The difference in distance between the two dyes indicated the amount of bone formation. The mechanically loaded bones showed significant evidence of formation and also significant numbers of active osteoclasts indicating high bone turnover. No evidence of necrosis or cartilage formation was found. Formation in unloaded bones was much reduced and on many areas no active osteoblasts could be observed. This is the first demonstration of bone formation ex vivo after 30 days of culture.

We gratefully acknowledge support by the German Arthrose Foundation (DAH) and the AO in Davos, CH. DJ is a recipient of a Fork award from the AO

Purpose: Radiologists describe cysts of the anterior cruciate ligament (ACL) as a cystic formation of the cruciate tentorium. The estimated prevalence is 0.2 to 1.3% of patients explored by magnetic resonance imaging. The purpose of this study was to better define the clinical symptoms involved by comparing clinical, radiological and pathological findings.

Material and methods: Between February 1996 and April 2000, nine men underwent surgery of the anterior cruciate ligament for cysts. Mean age at surgery was 43 years (26) 54). None of the patients had a history of trauma and one patient had undergone medial meniscectomy 12 months earlier due to meniscosis. Pain had been present for six months to seven years and progressed slowly. It was very specifically related to hyperflexion. Five patients exhibited a moderate effusion and five had a painful joint line. The Lachmann was stiff. Single leg stance plain x-rays were normal. Magnetic resonance imaging demonstrated a poorly delimited heterogeneous destructured aspect of the ACL in seven patients. The suggested diagnosis was “partial tear of the ACL or old tear of the ACL”. A perfectly circumscribed cyst was revealed by the MRI in two cases, lying behind the ACL in the tentorium of the notch. The posterior cruciate ligament had a normal aspect in all cases.

Results: All patients underwent arthroscopy. The ACL was deorganised, widened and yellow in eight, with a yellow circumscribed nodule on the posterior aspect in one. An impingement between the ACL and the tentorium of the notch was observed in one case. Total synovectomy of the ACL sheath removing part of the ligamentous fibres was performed in eight cases. An isolated cyst was removed in one. Plasty of the notch was performed in one. Pathology reported degenerative dystrophic lesions in eight cases and haemopigmented villonodulary synovitis in one. All patients were reviewed at a mean follow-up of 14 months (8–48). Pain at hyperflexion had completely subsided and there was no hydrarthrosis. The Lachmann was stiff and symmetrical.

Conclusion: The term ACL cyst is probably inappropriate because we were unable to find true cystic formations but rather a spontaneous degenerative process. Synovectomy of the sheath gave good clinical results. MRI findings can be a diagnostic pitfall: a destructured aspect of the ACL without a context of trauma should suggest spontaneous degeneration of the anterior cruciate ligament.

Purpose: The purpose of our study was to evaluate, in a context of laxity, the incidence of meniscal lesions and their treatment on the osteoarthritic evolution after more than ten years. In 1986 and 1987, we operated 230 knees with tears of the anterior cruciate ligament using a patellar graft. Among these knees, 184 (80%) were reviewed clinically and radiographically for this study.

Material and methods: Ninety patients (49%) had healthy menisci at the operation and did not have a secondary meniscal procedure; 94 patients (51%) had a meniscal procedure before, during or after the plasty. Among these, 13 (14%) had had an earlier meniscectomy, 18 (19%) had had meniscectomy at the time of the plasty (two revisions), 35 (37%) had had sutures (five secondary failures), ten (11%) had had a long injury left in place (four revisons), and 18 (19%) with normal knees at the time of the plasty had a secondary meniscectomy.

Results: We compared the radiological results in these different populations (osteoarthritis with remodelling compared with normal images). There was a significant difference between the population with normal knee images and the population with meniscal lesions irrespective of the time of treatment (prior meniscectomy, concomitant meniscectomy and plasty, healthy menisci at the time of plasty but secondary meniscectomy). There was no significant difference between the knees with normal menisci and those with sutured menisci.

Conclusion: Saving the meniscus has a major effect on the radiological evolution of the knee. Thus isolated meniscectomy should not be performed for laxity in young patients; meniscal lesions should be sutured at the time of ligamentoplasty.

Because there are a number of complicating factors, total hip arthroplasty (THA) performed following acetabular fractures has a less favourable prognosis than when done for primary degenerative arthritis. Patients who have had ace-tabular fracture and present for consideration of THA need careful clinical and radiological assessment. Investigation should include AP and lateral radiographs, 45° inlet/outlet views, obturator and iliac obliques, Judet views and CT scan, with or without 3D reconstruction. There are various classifications defining whether the bone deficiency is contained or uncontained and the extent of the structural defect. Treatment options include autograft, allograft together with mesh, screws, plates, rings, cages, etc.

It is probably preferable to undertake THA sooner (as soon as there is radiological evidence of incongruent articular surfaces) rather than later, as this reduces the delay between fracture and recovery from THA, and any inadequate reduction can be minimised or corrected. The surgical approach must allow adequate access for the intended reconstruction. Small contained or uncontained defects can be treated with cemented or cementless implants and limited grafting. Large defects require structural reinforcement, bone grafting, a retaining cage and, unless a custom-made implant is used, cemented fixation.

Potential problems at the time of surgery include sciatic nerve injury (beware the ‘double crush syndrome’) obstructive hardware, heterotopic ossification, avascular necrosis of the acetabulum and occult infection. Patients who are elderly or who present with markedly impacted fracture, extensive abrasion or fracture of the femoral head, displaced femoral neck fracture, and extensive acetabular comminution in the presence of osteopoenic bone, may warrant acute management with THA.

Early experience of THA in the treatment of selected acute fractures is encouraging. However, the clinical results of THA after fractures of the acetabulum are often disappointing, and there is no current evidence that open reduction and internal fixation improves the success of the subsequent THA.

THA following acetabular fractures is a challenging procedure with a high complication rate. Appropriate investigation and preoperative planning reduces the risk of complications.

Introduction: Gait initiation is a sequence of stereotypical postural shifts culminating in a forward step. Muscular and gravitational forces interact leading to appropriate dynamic conditions that allow progression. This requires a complicated system of neural and muscular control. Derangement of ground reaction forces during gait initiation may be a more specific indicator of neuromuscular disease than steady state gait.

Little work has been done on gait initiation in children and there is no published data on gait initiation with cerebral palsy. The aim of this study was to examine the ground reaction forces and centre of pressure in normal children during gait initiation, to compare these to similar values in hemiplegic children and to try to identify differences between the two which may be diagnostic for hemiplegia.

Patients and methods: Five normal and five hemiplegic children were studied. Kinematic and dynamic data were collected using a CodaTM motion analysis system and KestlerTM force plate. All subjects stood with one foot on and one foot off the force plate and walked off upon hearing an audible cue. Tests were repeated measuring right and left, normal and hemiplegic legs as both stance and swing legs. Ground reaction forces in the X,Y and Z axes, centre of pressure and kinematic data were collected and studied.

Results: 1) Normal children. In the vertical direction for the stance leg there is an initial fall in GRF, followed by a bimodal peak in GRF. In the fore-aft direction the GRF is initially directed backwards and subsequently has a bimodal forward force.

Medio-laterally the stance GRF tending to adduct falls initially and subsequently rises with a bimodal peak. The forces in the swing leg reciprocate these forces.

2) Hemiplegic children. The overall pattern seen when the normal leg is the stance leg are similar to those in normal children with certain specific variations in force development and magnitude. When the hemiplegic leg is the stance leg the overall patterns are again similar but considerably less smooth with characteristic changes indicative of neuro-muscular disturbance. The initial “adjusting” forces tend to be larger indicating the greater force required for control.

Discussion: The pattern and relative magnitude of forces measured for normal children are identical to those previously reported for adults. This validates our study design and indicates that central programming for gait initiation develops early in life. It is therefore an early developmental skill and may be used as a diagnostic test in childhood. Significant variations are seen in cerebral palsy. Knowledge of these specific changes may allow earlier and more accurate diagnosis of cerebral palsy in children under investigation for movement disorders. Normal GRF patterns during gait initiations may provide early reassurance for parents of children suspected of having cerebral palsy.

Introduction: The infrapatellar fat pad was first described in 1904 by Albert Hoffa. Sometimes disregarded, it is apparent that the infrapatellar fat pad is of importance to knee joint function as fat at this site is only lost in severely emaciated individuals. Also, recent MRI studies have described various pathological changes affecting the fat pad. This study examined the anatomy of the infrapatellar fat pad in relation to knee symptoms and surgical approaches.

Materials and Methods: 8 preserved knees were dissected via semicircular parapatellar incisions extending from the tibial tubercle to the superior patellar border and including the quadriceps muscle 13 cm above the superior border of the patella. The synovial membrane of the joint and the ligamentum mucosum were divided and the tibial tubercle was then excised. The resultant tissue complex was removed and the fat pad dissected away from surrounding structures. The appearance, volume and presence of any clefts in the pad were recorded. The cadaveric dissections were then compared to direct observation of the fat pad during total knee replacement, during arthroscopy and on MR imaging.

Results: The infrapatellar fat pad was found to be present in all cases. It had a consistent shape consisting of a central mass with medial and lateral extensions. The ligamentum mucosum was attached to the intercondylar notch of the femur in all cases and measured an average of 15.7mm at its base. A horizontal cleft was found in 6 cases and a vertical cleft was found in 7 cases. Both have been previously noted. A tag extended superiorly from the posterior aspect of the fat pad in 7 cases. The volume of the fat pad had quite a large range among individual cadavers (average volume was 24 ml, range: 12–36ml). The intra-individual variation was smaller with an average difference of 4ml (range:2.7ml) between knees.

Discussion: The infrapatellar fat pad has been implicated in a wide variety of conditions affecting the knee joint. It has been shown to be involved in arthofibrosis of the knee following surgery, patellar tendonitis, formation of intra-articular fibrous bands, and a site of an ossifying chondroma. It seems that fat pad pathology is usually secondary to other knee joint pathology and primary involvement is rare. The presence of clefts in the fat pad is of importance as a distended cleft may mimic an abnormality and an abnormality in the cleft may be overlooked on imaging of the knee joint. The appearance of the fat pad on direct visualisation in the living person presented a fat pad with a more globular appearance than that seen in the cadaver. The clefts were clearly visualised on MRI.

Conclusion: The infrapatellar fat pad is a structure that is consistently present in the knee joint. It consists of a central body with medial and lateral and medical extensions. It usually contains a vertical cleft located superiorly and a horizontal cleft located inferiorly as well as a tag of fat extending superiorly, which forms the roof of the vertical cleft. The infrapatellar fat pad is attached to the intercondylar notch of the femur by the ligamentum mucosum and is firmly anchored to the patella by dense fibrous tissue.

The Exeter totally collarless, double-tapered femoral component was developed in 1969 jointly at the School of Engineering at the University of Exeter and the old Princess Elizabeth Orthopaedic Hospital. At the time, in common with a number of implants in contemporary use, the new Exeter stem was manufactured from the rather ductile stainless steel EN58J. The original version of the Exeter stem had a polished surface. This feature was not part of the original design specification, but was demanded by the current British standard governing the use of EN58J in orthopaedic implants. At that time, no thought was given to the possibility that the surface finish of the stem might influence outcome.

Used from 1970 to 1975, the original stems rarely came to need replacement because of loosening. The major complication was the incidence of stem fracture, first seen in 1973, which has reached 4% over a 25 to 30 year follow-up. A stronger stem was introduced at the beginning of 1976. This was manufactured from 316L. As there was no standard demanding a polished surface, this stem was manufactured with a surface two orders of magnitude rougher than the surface of the original polished Exeter stems. While the introduction of this stem almost completely solved the problem of stem fracture, with it appeared notable problems of femoral endosteal bone lysis and aseptic stem loosening, hardly seen with the original polished stems. The study of retrieved prostheses showed the matt surface stem to be prone to abrasive wear against the inside of the cement mantle, and that this phenomenon could lead both directly and indirectly to stem loosening.

Unfortunately, a decade passed before the polished stem was re-introduced in 1986. A monobloc version was used until the beginning of 1988, when the modular Exeter Universal stem was introduced. With both the monobloc and modular versions of the polished Exeter stem, both aseptic loosening and localised endosteal bone lysis have become rare.

Further retrieval studies have shown that in polished and matt Exeter stems the wear processes between stem and cement are fundamentally different. This difference may explain the substantial clinical difference in outcome between these two types of stem. These considerations lead to the view that abrasive stem wear in matt stems is probably a major cause of failure, and more important than failure of cement.

Purpose: En bloc resection can be proposed for lung cancer involving the apex with invasion of the ribs or the transverse process using a transcervical anterior approach. Cancers invading the intervertebral foramen cannot be resected via this approach despite the classical indication for surgical resection. We report results of a novel surgical technique allowing cancerological resection of these tumours.

Material and methods: Fifteen patients with the same grade of cancer were operated using the same surgical technique. The first operative time included: superior lobectomy via anterior cervicothoracic access (without removal of the lobe), dissection of the subclavian vessels and the brachial plexus, section of the ribs and the T1 root, spinal exposure from C6 to T5, hemi-disectomy C7-T1 and discectomy at the level below the invaded foramen, medial vertebral groove, closure. The second operative time included: posterior access, extended instrumentation of the spine, hemi-laminectomy C7 extended as needed, section of the roots (depending on the level of the resection) within the canal, oblique posterior vertebral osteotomy along the medial border of the pedicle terminating in the anterior groove. Finally en bloc ablation via the posterior access of the surgical piece including the lung, the ribs and the hemi-vertebrae.

Results: Three- and four-level hemivertebrectomy was performed in eleven and three patients respectively. One patient had two hemivertebrectomies associated with one vertebrectomy. There were six resections (with repair) of the subclavian vessels for tumour invasion. Peroperative mortality was zero. Mean blood loss was 3000 ml. There were no neurological complications. There were eight postoperative complications: pneumonia five patients, cerebrospinal fluid fistula one patient, skin dehiscence one patient, haemorrhage one patient requiring reoperation. All patients were given postoperative radiotherapy. Three- and five-year survival was 36% and 27% respectively. Among the nine deaths, three had local relapse and six had general relapse.

Discussion: This techniques enables resection of tumours considered to be inextirpable using other techniques. Survival was the same as for tumours of the apex without invasion of the foramen and better than without surgery. This major surgery requires a well-trained multidisciplinary team (thoracic and vascular surgeons, spinal surgeon, anaesthesiologists, intensive care specialists). Contraindications for this type of surgery are invasion of the spinal canal, the brachial plexus and the vertebral body as well as the presence of a spinal artery entering the foramen to be resected.

Purpose: Use of massive allografts for reconstruction of major bone stock defects remains a controversial issue. We reviewed our experience to compare results with other methods, particularly free vascularised bone transfer reconstructions.

Material and method: Between 1983 and 1995, 36 patients (15 men and 21 women) underwent cancerological resection of a long bone shaft for primary malignant tumour. Mean age was 19 years (8–84). The tumour was a high-grade sarcoma in 26 cases, low grade sarcoma in eight and adamantinoma in two. Mean length of resection was 19 cm (14–34). Cryopreserved allografts were used in 24 cases, gamma irradiated allografts in 12. Various osteosynthesis procedures were used, generally combining an axial assembly with a single or dual epiphyseal construct. Localisations were: femur 24, tibia ten and humerus four. All patients were reviewed at a minimum follow-up of five years (range 5–16 years, mean 8 years). Functional outcome was assessed with the Enneking criteria. Bone healing at junctions was considered to be achieved when there was no clinical expression and radiographic images remained unchanged for two years.

Results: All immediate complications were infections (one femur four tibias) and required partial or total ablation of the allograft in four cases and amputation in one (tibia). The predominant late complications were late consolidation (n=13) and stress fracture of the allograft (n=6). Six patients died before bone healing and were not retained for analysis. Among the 28 patients retained for analysis (eight excluded: six deaths, one amputation, one total ablation of the allograft), only ten achieved bone healing after one procedure. The other eighteen required on the average four reoperations to achieve consolidation (3–11 procedures for osteosynthesis and new allograft material). All patients had achieved bone healing at last follow-up. Functional outcome was excellent for femurs, good for tibias, and fair for humeri due to the impact on shoulder function. There was no significant difference in consolidation with cryopreserved and irradiated bone material but two irradiated grafts could not be used correctly because they were to friable.

Discussion: These more or less satisfactory results must be examined in light of the context. Cancerologicl resection (periosteum + soft tissue), generally combined with adjuvant treatment (chemotherapy for 24 patients and radiotherapy for three), places the patient in conditions highly unfavourable for bone healing. Use of allografts alone, combined with approximate fixation procedures early in our experience, demonstrated the limitations of the technique (only two primary consolidations among 18 patients). However, when the allograft was combined with axial fixation and immediate allograft or allograft after adjuvant treatment, primary consolidation was achieved in 80% of the cases (eight out of ten). All patients who achieved long-term remission conserved a functional limb with relatively preserved bone stock.

Conclusion: Despite controversial results, massive allograft reconstructions can provide a useful alternative to fill major bone stock defects of the femur or humerus. For the tibia the risk of infections may require further discussion before determining the best approach. These results should be compared with those in a homogeneous series of patients treated with a vascularised free bone transfer, but to our knowledge no such series is available in the literature.

Because there is little in the literature about specific presentation and examination methods for acromioclavicular (AC) joint pathology, we aimed to define and identify the most reliable tests.

We identified and examined 30 patients with probable AC joint pathology. We then excluded eight patients who experienced no pain relief after local Lignocaine infiltration, and examined 22 patients, two of whom had bilateral shoulder problems.

There were 15 complaints of AC joint pain, 13 of anterior pain, five of posterior pain and five of lateral pain. Pain radiated anteriorly in 14 patients, posteriorly in two, laterally in three and to the cervical region in three. Pain increased with weight-bearing in 18 shoulders, on elevation in five, on activities of daily living in six, at night or on being lain on in 11, and on reaching across the body in three. Clinical examination revealed swelling in seven shoulders and AC joint prominence in seven. There was local tenderness in 21 shoulders and there were crepitations in four. The forced cross-body test produced pain in 22 shoulders. In 22 shoulders, elevation was less than 60°. Jobe’s test was positive in 20, the Speed’s test in 19, O’Brien’s test in 15, the compression test in 15, the distraction test in 13. A painful arc was present to 160° in 13 shoulders. There was neck tenderness in 13 patients. Associated conditions included two cases of shoulder arthritis, six of impingement, two rotator cuff tears, two cases of biceps tendinitis and two of cervical pathology. Radiological changes were evident in 19 AC joints, 13 shoulder joints and 11 cervical spines. On ultrasonography, pathology was resent in 10 of 15 cases.

The most common symptoms were pain with weight-bearing, elevation and lying on shoulder. Anterior and posterior pain was the most common. The most common clinical findings were local tenderness, pain on elevation and the forced cross-body test, positive Jobe’s and Speed’s tests. Because no test is 100% accurate, the whole clinical presentation must be taken into account. Local infiltration of the AC joint is extremely helpful.

Purpose: Recovery of muscle function after nerve repair remains incomplete despite progress in microsurgical techniques. Potential for muscle recovery could be greatly improved. The purpose of our study was to demonstrate the functional impact of exogenous satellite cells in degenerated muscles.

Material and methods: We used the anterior tibialis muscle (Ta) in rabbits (n=24) as our experimental model. Muscle degeneration was created by bilateral injections of cardio-toxin into the Ta. Five days later, the left Ta was injected with autologous satellite cells (SC) at multiple points. The same volume of culture medium was injected into the right Ta. Two months later, maximal isometric muscle force and stress resistance of the Ta was measured. Histoimmuno-chemical labellings were made.

Results: The volume of cardiotoxin injected created two categories of muscles: recovery of former function was not possible with low dose cardiotoxin injections. Maximal isometric muscle force was less than 35% of the control. Transfer of SC restored nearly normal muscle force. Resistance to stress followed the same pattern. Recovery of maximal muscle force was possible with high-dose cardiotoxin injections. Resistance to stress was greater than the control (+ 35%). Transfer of SC did not modify results.

The weight of the Ta increased for both cardiotoxin doses. There was an increase in the size of the fibres with or without SC transfer.

Discussion: Injection of cardiotoxin induced muscle degeneration. With greater muscle degeneration, regeneration of muscle capacity was greater. Transfer of SC improved the functional result when muscle degeneration was incomplete. Improved resistance to stress after injection of high-dose cardiotoxin could result from changes in muscle myosin and fibrillary structure.

Conclusion: Further studies are needed before clinical application to better understand the underlying mechanisms operating with satellite cell injections. Many applications could be proposed, particularly for surgical nerve repair, ischaemic heart failure, and myopathy.

We reviewed the outcome of prosthesis-to-bone fixation of the rough titanium femoral stem of an Ultraloc prosthesis (Zimmer, USA).

Between 1989 and 1991, 41 of 55 patients were traced for long-term review at a mean of 107 months (55 to 139). The primary pathology was avascular necrosis in 18 patients, osteoarthritis in 16, ankylosing spondylitis in two and Perthes’ disease in one, and there were two cases each of trauma and dysplasia. There was an equal number of men and women, whose mean age at operation was 47 years (24 to 66).

Radiological assessment of the stems revealed well-fixed stems in 40 patients (97.6%). In 20 stems small granulomata due to polyethylene wear were found in Gruen zones 1 and 7, and in one stem in zones 1, 6 and 7. Only one stem required revision for loosening (done at 59 months), but cups (48.8%) were loose. Three patients required revision owing to polyethylene wear and one for sepsis. In all four cases, removal of the stem was extremely difficult. The remaining 16 hips await revision.

Although the results obtained using an Ultraloc prosthesis are poor, from the point of view of fixation the stem has functioned successfully. However, the formation of granulomata causes cup loosening.

We retrospectively reviewed 10 children treated for tuberculosis of the elbow over a 21-year period from 1979 to 1999.

The mean age at diagnosis was 5.5 years (1 to 11). The median duration of symptoms was 10 weeks (l week to 18 months). The patients presented mainly with swelling of the elbow joint due to synovitis. Radiological appearances of the elbow at presentation were assessed according to Kerri and Martini’s classification. One elbow was stage I (osteopoenia), eight were stage II (osteopoenia and erosions) and one stage III (joint space narrowing).

Open biopsy was performed on all patients. There was positive histology (caseating granuloma) and/or positive culture in eight patients. Of the two patients with non-specific histology and negative culture, one was found on chest radiograph to have tuberculosis involvement and the other healed on anti-tuberculosis therapy. All patients were treated with rifampicin, isoniazide and pyrazinamide for nine months. No synovectomy was done. Postoperatively all patients were immobilised in a backslab and then actively mobilised.

At a mean follow-up of three years (1 to 10), patients were assessed according to a modification of Kerri and Martini’s classification. Seven of the eight stage-I or stage-II patients had an excellent result (full range of movement) or good result (loss of less than 30% of range of movement). One stage-II patient had a fair result (loss of range of movement of 30% to 50%). The stage-III patient had a poor result (loss of more than 50% of range of movement).

We concluded that elbows with stage-I and stage-II disease (synovitis) have a good outcome. Anti-tuberculosis chemotherapy is effective in the treatment of stage-I and stage II disease. Synovectomy is unnecessary.

Intervertebral disc cells exsist in a precarious nutritional environment. Local concentrations depend on both nutritional supply and demand. Little is known about the metabolism of disc cells; existing data focuses on intact tissue, where the local metabolic environment is unknown. We have thus developed a closed chamber to study the metabolism of isolated cells under controlled conditions.

Bovine disc cells were isolated from coccygeal discs and transferred to the sealed chamber, in which embedded electrodes measured pH, pO2 and glucose concentration, and a port allowed sampling and addition of metabolic reagents. Metabolic rates were assessed from concentration changes. Cell viability was assessed and intracellular ATP measured at completion of each experiment.

Under standard conditions, metabolic rates were similar to those measured in tissue, with a glucose:lactic acid ratio of approximately one to two. We have also examined the effect of extracellular pH on nucleus pulposus cell metabolism. Between pH 7.4–6.8, metabolism is insensitive to extracellular pH, and lactic acid production agrees with the literature 1, 2. Below pH 6.8, lactic acid production fell linearly with decreased pH. At pH 6.4, lactic acid production had fallen by 60%, and intracellular ATP by 80%.

These results show a fall in lactic acid production with extracellular acidification, which in vivo arises mainly from lactic acid produced by the cells. This may be protective. However the decrease in metabolism, and hence loss of ATP, may have a detrimental effect on the cells. There is thus a complex interplay between different components of the nutritional environment. Investigating these in combination should give valuable information about disc cell metabolism, as changes in cells metabolism can affect nutrient availability and hence cellular activity and viability.

Horse riding is a common pursuit and is more dangerous than believed. Most injuries of the hand and wrist are caused by falls, as in other sports. However, exclusive to riding are injuries sustained whilst leading a horse. Avulsion injuries are well recognised but little has been reported on phalangeal fractures in this situation.

We report on seven cases that required hospitalisation in our hand unit, for injuries from horses over a two year period. Six of these patients sustained multi-fragmented spiral periarticular fractures involving the middle and proximal phalanx and one a horse bit.

We will discuss in detail the mechanism of their injuries, the surgery undertaken, their post-operative rehabilitation and overall outcome. Furthermore we review the recommended horse handling technique and contrast it with the mechanism of injury in our cases.

In our experience the fractures seen were unstable, comminuted and needed internal fixation. One patient developed a delayed union and three post-operative stiffness. Our results suggest that fractures whilst leading horses are more complex than recognised, usually need surgery and often have a relatively poor outcome. All of these cases were largely preventable and could be attributed to incorrect horse leading technique.

This study compared the effect of manipulation with a period of normal activity on the range of intervertebral sidebending.

Thirty asymptomatic male volunteers were randomised to treatment or control groups. All were subjected to low-dose X-ray screening through 80° of passive lumbar spine side-bending. Motion sequences were digitised at a 5Hz sampling rate. The treatment group (n=16) had rotary manipulation to each lumbar linkage, followed by normal activity. The control group (n=14) had normal activity only. Both groups were then re-screened. Each vertebral pair was tracked and intervertebral rotation throughout the motion measured. Three subjects were analysed 10 times for reliability and all intervertebral motion was tracked twice.

Twenty-one manipulated linkages and 10 controls met the reliability criteria. For non-manipulated segments the mean range at first screening was 14.2° (SD 1.39) and manipulated segments 12.8° (SD 3.81). The range of the non-manipulated segments increased by +0.9o and the manipulated segments by +0.4°.

The change in manipulated segments was negligible and similar to controls, although the instrument can be sufficiently reliable to measure a 2° difference. The technique is sufficiently robust to determine if spinal manipulation changes these ranges in selected patients.

In order to assess the incidence of avascular necrosis (AVN) following septic arthritis of the hip in children, we retrospectively reviewed the outcome of 227 hips with septic arthritis treated over an 18-year period. The mean age at presentation of the 221 patients, six of who had bilateral conditions, was 5.6 years (5 months to 14 years).

All patients underwent open arthrotomy and pus was found at surgery. Patients were treated with cloxacillin and patients aged six months to two years also received ampicillin. Staphylococcus areus was cultured in 51% of hips, Haemophilus influenzae in 9%, Streptococcus pneumoniae in 4% and Streptococcus pyogenes in 6%. The remaining 30% had no growth. Septicaemia was present in 20 patients at presentation.

AVN developed in 24 hips (10.5%), and chondrolysis in five (2.2%). Of the hips with AVN, seven were septicaemic. The most important factor in the development of AVN was a delay of five or more days from onset of symptoms to surgery. The risk of AVN with five days’ delay was 50% and increased exponentially with a longer delay. Septicaemia did not constitute a risk per se, but did contribute to a delay in diagnosis of hip involvement. The total head was involved in 14 of the 24 hips with AVN, while 10 had partial head involvement, with a better long-term outcome.

Nitric oxide (NO) production by the inducible NO synthase (iNOS) and enhanced emigration of leukocytes into synovial tissue are suggested to play a crucial role in mediating chronic joint inflammation such as rheumatoid arthritis. The effects of iNOS inhibition in experimental arthritis are dicussed controversally. The aim of our study was to analyze the synovial microcirculation and leukocyte endothelial cell interactions in iNOS-deficient mice with antigen-induced arthritis (AiA) in vivo. 14 homocygote iNOS-deficient (iNOS KO C57BL6/J x 129SvEv; Merck & Co., Rahway, NJ, USA) and 14 iNOS-positive (C57BL6/J x 129SvEv) mice were used for our study. The patella tendon was resected, which allows for visualization of the intraarticular synovial tissue of the knee joint using intravital fluorescence microscopy. Animals were allocated into four groups (iNOS +/+, iNOS +/+ with AiA, iNOS −/− and iNOS −/− with AiA) (n=7 each group). On day 8 after arthritis induction, functional capillary density (FCD), fraction of rolling leukocytes, and the number of adherent leukocytes were quantitatively analyzed in synovial postcapillary venules. Histologic sections were performed to assess leukocyte infiltration of the synovium.

FCD or leukocyte-endothelial cell interaction were not altered in healthy iNOS-deficient mice in comparison to iNOS +/+ animals. However, in iNOS-deficient animals with AiA there was a significant increase in the fraction of rolling (0,510,05) and in the number of adherent leukocytes (729126 mm-2) in comparison to wild type mice with AiA (0,330,07 and 565110 mm-2) (MWSEM, p < 0,05). Histologic sections revealed increased leukocyte infiltration in iNOS-deficient animals with AiA compared to iNOS +/+ arthritic animals.

In our study, there was an enhanced leukocyte accumulation and extravasation in iNOS-deficient mice with antigen-induced arthritis in comparison to iNOS-positive animals with arthritis. Thus, the induction of iNOS appears as critical protective response to AiA possibly by reducing leukocyte adhesion and infiltration.

Edema and infection represent serious complications of blunt extremity trauma. It is important to differentiate between pathophysiological changes within tissues proximal and within distal to the site of trauma. The aim was to investigate the effects of soft tissue trauma on the microcirculation of the mouse lower limb. Endothelial leakage and leukocyte accumulation proximal and distal to the site of trauma were studied using intravital fluorescence microscopy.

Low-energy trauma to the lower limb was defined in previous experiments as a trauma transferring 50% of the energy required to produce tibial fracture. The trauma was inflicted under general anesthesia by an accelerator, hitting the mid-section of the calf in a perpendicular direction. 5, 90, and 180 minutes after trauma, the following microcirculatory parameters were measured: diameter of arterioles, venules, functional capillary density (FCD), extravasation of FITC-dextrane, and leukocyte-endothelial cell-interactions. Two groups (control and trauma) were studied proximal to, distal to and at the site of trauma. Skin, subcutaneous tissue and muscle were investigated individually in the trauma and the control groups (each group n=7).

At the site of trauma, distinct extravasation and edema formation in all tissues was observed. In subcutaneous and muscle tissue, microvascular thrombosis as well as edema were detected proximal and distal to the trauma. FCD was reduced in muscle and fat tissue. The numbers of rolling and adherent leukocytes were enhanced 5 minutes after trauma and throughout the observational period.

Our results demonstrate endothelial leakage and extravasation early after low-energy soft tissue trauma in all soft tissues proximal and distal to the site of trauma. In addition, we found high accumulation of leukocytes in all locations, especially in soft tissues. The model presented is ideally suited for the in vivo investigation of new therapeutic strategies for edema and thrombosis prevention in animals with soft tissue trauma.

To assess the role of pelvic osteotomy during the closure of bladder and cloacal exstrophy, we retrospectively reviewed 10 patients treated from 1990 to 1999.

Six patients had cloacal exstrophy and four had bladder exstrophy. Two patients had no primary osteotomy. Two had posterior, two anterior pubic and two midiliac oblique osteotomies. Osteotomies were performed at a median age of 5.3 weeks.

The mean follow-up time was five years (2 to 11). We assessed facilitation of closure, reconstitution of pelvic anatomy, maintenance of interpubic distance (IPD), urinary continence and gait.

All osteotomies facilitated soft tissue closure at the time of surgery. Subjectively, the best restoration of pelvic anatomy was with a midiliac oblique osteotomy. In all patients, IPD increased progressively with increasing age (mean pre-operatively 3.3 cm, postoperatively 1.9 cm and 5.0 cm at follow-up).

The results of soft tissue surgery to provide continence and maintain abdominal wall closure were poor. All procedures to address incontinence failed and there was a 100% dehiscence/sepsis rate. Although half the children had increased external rotation of the hip at review, only one child had an externally rotated joint. .

The current long term results of total joint arthroplasty are limited by mechanical wear of the implants with an associated immune mediated bone lysis with subsequent loosening and eventual failure. It has been demonstrated that the osteolysis seen in cases of aseptic loosening is mediated by the immune system, particularly, both directly and indirectly, by activated macrophages. Macrophages indirectly cause osteolysis through release of the osteoclast activating cytokines: TNFα, IL-1 and PGE2 and also directly resorb bone in small amounts when activated by wear particles.

We wished to determine if macrophage activation and the release of osteolytic cytokines in response to orthopaedic wear debris could be suppressed pharmacologically, with the use of anti-inflammatory and anti oxidant agents.

We utilised established cell culture models of both peripherally derived monocyte/macrophages and lymphocyte enriched co-cultures and examined the effects of polymethylmethacrylate particles alone on the cells in culture. The effects of anti-inflammatory and anti-oxidant agents (dexamethasone, diclofenac and n-acetyl cysteine) in varying concentrations were then examined using ELISA of cytokine release and electron microscopy to examine ultra structural responses.

Cell viability was also measured in cultures over 24 hour periods (at 6, 12 and 24 hours) using Trypan blue exclusion and Coulter counter, while cell type and morphology were determined cytologically, including α-naphthyl acetate esterase cytochemical identification and electron microscopy. The use of N-acetyl cysteine was associated with very significant suppression of TNFα, IL-1β and PGE2 in both macrophage and lymphocyte enriched co-culture with no effect on cell viability. While diclofenac was also associated with significant decreases in cytokine expression it was associated with a decrease in cell viability that approached significance. Dexamethasone did not have a reliable effect on these cytokines. Ultra-structural electron microscopic examination of the cells also demonstrated signs of definite down-regulation of cytoplasmic and nuclear activation.

We have demonstrated, therefore, that novel anti-oxidant therapies and possibly other immune modulating drugs can eliminate the activation of macrophages in response to peri-prosthetic wear particles without any associated decrease in cell viability and thus may provide a means of reducing the incidence of loosening and failure of total joint arthroplasty.

Over a 4 year period 27 children with cerebral palsy underwent proximal femoral derotation osteotomy resulting in a total of 42 operations performed. Each of these children had pre operative gait analysis performed followed by derotation osteotomy. The degree of derotation varied individually and was judged to be correct when the foot lay in a neutral position. Gait analysis was not repeated until 1 year after surgery to allow for complete bony union, recovery of the soft tissues and general patient rehabilitation. Pre-operative and post-operative data were compared to give a quantitative analysis of the actual derotation obtained.

The mean age at the time of operation was 9.7 years (range 4.5–14.5 years). The male : female ration was 6 : 5. the mean amount of femoral derotation achieved was 26.25 degrees (minimum 7 degrees, maximum 66 degrees). The goal of the operation was to correct internal rotation and achieve a hip in a neutral position throughout the majority of the gait cycle. The average hip rotation in a normal able-bodied person is 1.72 degrees of external rotation. 84% achieved more than 75% derotation to neutral. The remainder were considered operational failures.

These results quantitatively demonstrate that proximal femoral derotation osteotomy is a successful operation in cerebral palsy to correct intoeing.

Chondrocyte sensitivity to strain depends on signal transduction pathways which include integrin-dependent increases in intracellular calcium. Human articular chondrocytes were cultured as monolayers in silicone dishes. After loading the cells with the calcium-fluorescent dye Fluo-3/AM the dishes were mounted in a 4-point bending apparatus and then fixed to a laser scanning confocal microscope. Biaxial substrate strain (15 000e) was applied to the silicone dish via a hand operated cam rotated at ~60 RPM (1 Hz) for 10 or for 50 cycles. Changes in intracellular calcium in single cells were determined by measuring the mean pixel values in the basal and stimulated images taken at different time points. The data reported for 50 cycle treatments represent 49 single cells of six independent cell isolations. The data for 10 cycle strain treatment are from a single experimental setup.

Increases in intracellular calcium were consistently observed in chondrocytes exposed to 15 000me for 50 cycles in a range from 1.3- to 4.0-fold with an average of 2.3-fold (SD=0.79). Few cells responded before 30 minutes but most of the responses occurred 30–60 minutes after strain. Consistent intracellular Ca++-increases were also seen after 10 strain cycles, however responses were detected within 5 minutes post-strain. The relative increase (2.7-fold ± 1.7) was similar in magnitude to 50 cycle responses.

Intracellular Ca++-fluxes in chondrocytes and other cells occur by at least two different mechanisms: through stretch-activated channels in the plasma membrane permit immediate Ca++-influx during strain application or by Ca++-efflux from intracellular compartments stimulated by slower acting second messengers. Our results suggest that the early response to 10 strain cycles is due to Ca++-influx via membrane channels while the later response to 50 cycles is due to Ca++-efflux from intracellular compartments, probably mediated by cytokines released in response to an initial Ca++-influx from the medium.

Scoliosis is a disease characterised by vertebral rotation, lateral curvature and changes in sagittal profile. The role of mechanical forces in producing this deformity is not clear. It is thought that abnormal loading deforms the disc, which becomes permanently wedged. Modelling and in vitro studies suggest that such deformations should increase intradiscal pressure. Intradiscal pressure has been measured previously in a variety of clinical environments. The aim of this study is to measure pressure profiles across scoliotic discs to provide further information on the role of mechanical forces in scoliosis.

Pressure readings were obtained in consented patients with ethical approval using a needle-mounted sterilised pressure transducer (Gaeltec, Dunvegan, Isle of Skye) calibrated as described previously. The transducer needle was introduced into the disc of an anaesthetised patient during routine anterior scoliosis surgery and pressure profiles measured. Signals were collected, amplified and analysed using Power-lab and a laptop computer.

Pressure profiles across 10 human scoliotic discs from 3 patients have been measured to date. Pressures varied from 0.1 to 1.2 MPa.

Annular pressures showed high pressure, non-isotropic regions on the concave but not convex side of these discs.

Nuclear pressures recorded from the discs of these scoliotic patients were higher than those recorded previously in non-scoliotic recumbent individuals.

We want to prove that you cannot make a good fitting stem of a THP before surgery because the resulting shape of the femoral cavity is set after all the tools have been introduced in the femur.

We are fully aware that fit and fill alone is not enough to obtain good fixation therefor all the investigated implants were plasma spray coated with HA.

We’ve investigated two groups of patients:

Pre-operative group: custommade implant based on CT scans and manufactured before surgery The proximal part was size for size and coated with HA; the distal part is cylindrical (44 cases, followup from 1.6 years to 5.2 years)

The coating specifications for both groups were exactly the same.We’ve compared the Harris hip score for both groups and we’ve performed a radiolographical analysis.

Of the pre- operative group 6 protheses had to be revised.This results in a revision rate of 25 % which is not acceptable.In the peroperative group however, no revisions have been performed.

Radiografically the per-operative group showed much better results than then the pre-operative group.

The obtained results suggest that it is not only important to have a good bone growth initiator such as HA but the implant needs to be in close contact with the bone.This confirms the limited gap bridging capacity of HA which has been reported by several authors in the past. A close fit can only be obtained by designing and manufacturing the implant during surgery based on the actual size of the femoral cavity.

In total hip arthroplasty (THA), it is preferable that patients have an ideal preoperative Body Mass Index (within 20% of the normal). The purpose of this study is to determine whether patients maintain their preoperative reduced weight after THA and whether the effort of encouragement and cost of a dietician to lose weight preoperatively is worthwhile.

Conducted over five years, this study included 100 patients with a mean age of 62.5 years (34 to 83). Preoperative and postoperative weights were obtained from clinical records.

There was a postoperative weight increase in 51% of patients and a decrease in postoperative weight in 46%. Pre-operative weight was maintained in 3%.

Mature human intervertebral disc cells have generally been described as being either fibroblast-like or chondrocyte-like; i.e. appearing either elongated and bipolar or rounded/oval. Fibroblast-like cells are observed within the outer regions of the anulus fibrosus whilst chondrocyte-like cells are found in the more central regions of the disc. However, a few reports have noted that in some circumstances disc cells appear to extend more elaborate cytoplasmic processes into their surrounding extracellular matrix. In this study, we have examined healthy and pathological human intervertebral discs for the presence of the cytoskeletal elements, F-actin and vimentin.

Tissues examined included discs of no known pathology, discs with spondylolithesis, scoliosis specimens taken from the convex and concave sides, and degenerated discs. F-actin was not readily observed within discs cells but was a marked feature of vascular tissue within the disc and occasionally seen in infiltrating cells. Vimentin was more readily seen within cells of the inner anulus fibrosus and nucleus pulposus. In general, disc cell morphology was fibrocyte or chondrocyte-like; however, in spondylolisthetic discs, cells with numerous cytoplasmic projections were frequently observed.

The differential morphologies and cytoskeletal composition observed in disc cells may be indicative of variations in mechanical strains and/or pathologies, or indeed of cell function.

The ‘Pi’ plate is an anatomical titanium plate recently introduced for the internal fixation of comminuted intra-articular distal radius fractures. We report our experience with this implant in a prospective series of twelve patients with an average age of thirty six years (range, 26–52 years).

A dorsal approach with release of the EPL tendon and extra-compartmental exposure of the radius between the second and fourth extensor compartments was employed in all cases. Iliac bone graft and a styloid K-wire were used to augment the plate fixation. Post-operatively, active mobilisation was started after wound healing. Wrist motion and grip strength measurements were made at six weeks, three months and six months by the therapist. At six months, patients recovered an average of 85% of range of movement compared with the opposite wrist, except for palmar flexion (65%). No loss of reduction was observed on follow-up radiographs. Complications were compartment syndrome, intraoperative EPL rupture and two cases of extensor tendonitis requiring implant removal.

The ‘Pi’ plate affords rigid fixation of distal radius fractures permitting early rehabilitation. It is however a demanding technique that is not without complications.

Traditional biomedical/ergonomic occupational interventions to reduce work loss show limited success. Attention is now focussing on tackling the psychosocial factors that influence occupational back pain.

A workforce survey of Glaxo Smith Kline (reported to the Society last year) established that clinical and occupational psychosocial factors (yellow & blue flags) act independently and may represent obstacles to recovery. Consequently, a nurse-led intervention was devised. Occupational nurses at two manufacturing sites were trained to identify both clinical and occupational psychosocial factors, and address them using a basic ‘counselling’ technique that reinforces evidence-based messages and advice, along with availability of modified work. The program should ideally be implemented within the first days of absence, with ‘case-management’ by the nurse for a further 4 weeks. Control sites simply offer ‘usual management’. Outcomes at 12-month follow-up are rates for work loss/work retention.

The target for contacting the worker (3 days) was achieved at one site, but not the other (mean 12 days), thus exerting a differential delay in delivering the intervention. The lack of early identification at the second site was due to local reporting/recording mechanisms. This study reveals a third class of obstacles to recovery – black flags – company policies/procedures that can impede occupational rehabilitation programs.

We retrospectively reviewed 52 children treated for tuberculosis of the knee in the 21-year period 1979 to 1999.

The mean age at which the condition was diagnosed was 5.3 years (8 months to 13 years). The median duration of symptoms was four weeks (1 month to 3 years). All patients presented with swelling, mainly owing to synovitis. Pain was a symptom in only two thirds of patients.

Using Kerri and Martini’s classification of radiological appearances, 33 knees were stage I (osteopoenia), 15 stage II (osteopoenia with erosions), two stage III (joint space narrowing) and two stage IV (joint space narrowing with anatomical disorganisation). All knees had either positive histology (caseating granuloma) and/or a positive culture for tuberculosis.

Treatment was with rifampicin, isoniazide and pyrazinamide for nine months. No synovectomy was done. Of the 48 knees with stage-I and stage-II disease, 22 were immobilised for at least three months and 26 actively mobilised.

At a mean follow-up of five years (2 to 16 years), the results were classified according to Wilkinson. All stage-I and stage-II knees had an excellent result (full range of motion) or good result (more than 90° of flexion). Stage-III and stage-IV knees had a fair result (less than 30°of flexion) or poor result (ankylosis). In stage-I and stage-II knees, immobilisation did not affect outcome.

In the same period, 25 knees with a non-specific histology and negative culture presented the problem of the differential diagnosis between tuberculosis and particular juvenile rheumatoid arthritis (JRA). Of these 17 were subsequently diagnosed as JRA. A histological study assessed the value of synovial lining (SLC) hyperplasia. The sensitivity of SLC hyperplasia for JRA was only 53%. Synovial biopsies from 10 joints with tuberculosis (positive histology or culture) were subjected to the polymerase chain reaction test. The sensitivity was only 40% for tuberculosis.

Purpose: The MacIntosch method for reconstruction of the anterior cruciate ligament using a free intra-articular plasty with an extra-articular reinforcement was the classical treatment during the eighties for chronic anterior laxity. In 1992, we reported our short-term resuls in 180 cases. The purpose of this report is to analyse the results in 112 of these 180 cases with a mean follow-up of 14 years.

Material and methods: One hundred twelve knees operated between 1982 and 1987 were included in this study. There were 82 men (73.2%) and 30 women (26.8%), mean age 24.9±5.8 years. Mean follow-up was 165.3 ± 25.9 months. Mean delay from accident to repair was 30.9 months (3–144) and meniscectomy was performed in 88% of the cases, mainly for contact pivot sports (85%). All patients had an overt laxity (advanced in 73.2% or isolated in 26.9%). The MacIntosh plasty performed by arthrotomy used a patellar tendon with a quadriceps tendon band prolongation. Arthros-copy was performed prior to surgery in all cases. If the transplant was implanted over the top, the radiographic analysis of the tunnel position was only made for the tibia. An independent examiner reviewed all the patients clinically and radiographically using the IKDC criteria with instrumental KT 1000 measurements.

Results: Sports activities were resumed in 78% of the cases with a trend towards pivot sports without contact practised in an amateur setting. Subjectively, 69.6% of the patients were very satisfied and 25% were satisfied. The click was abolished in 83% of the cases, was minimal in 15% and overt in 2%. The medial meniscus was intact in 40% of the cases with only 10 secondary meniscal tears 14 years later. The residual manual maximal traction differential at KT 1000 was 1 ± 1.225 mm and the mean compliance was 1.69 ± 1 mm. The overall IKDC score was: 31% A, 47/6% B, 19.1% C, 1.9% D. X-rays were normal in 17%, showed remodelling in 55.4%, and joint narrowing < 50% in 23.8% and > 50% in 3.8%. For patients with an intact medial meniscus, joint narrowing was observed in 5.5% compared with 24% after resection of the medial meniscus. There were two repeat tears in this series compared with 22 tears of the contra-lateral anterior cruciate ligament. The unsatisfactory results (22%) were related to anatomic failure (two cases) and functional problems (18 cases, defective mobility and pain). The prognostic factors were age at time of operation and preservation of the medial meniscus.

Conclusions: This study confirms the persistently good clinical and functional results 14 years after plasty using the patellar tendon associated with lateral reinforcement. Ligament stabilisation was satisfactory but it must be recalled that at 14 years, the functional needs were different for these knees. The radiological course was more worrisome with joint narrowing in 27.6% of the cases.

This study investigated the effects of wear particles, produced from a number of implant materials, at the bone-implant interface using a small animal model.

Particles were prepared from metal, ceramic and polymer replacement joint components or implant grade stock by grinding the materials against a diamond embedded grinding pad. The mean diameter of the particles ranged from 1.5mm to 3.2mm. Sterilised particles were suspended in sterile saline containing 2% v/v male Sprague-Dawley serum at a concentration of 109 particles per ml.

Seventy-two male Sprague-Dawley rats were assigned to twelve groups of six animals. A ceramic pin was inserted into the right tibia of each animal. Six groups were assigned a particle type with one group acting as vehicle control. 100ml of particle suspension or vehicle was injected into each knee joint at 8, 10 and 12 weeks following implantation and the animals were killed 2 weeks later. Of the remaining five groups, four were assigned a particle type and one was the vehicle control. These animals were injected with 100ml of particle suspension or vehicle at 20, 22 and 24 weeks following pin implantation and were killed 2 weeks later. The tibia and femora were removed, disarticulated and processed for histology. The total gap between pin and bone, including fibrous tissue, was measured.

Specimens showed no signs of infection either clinically or in the histopathology. All materials tested produced lesions at the bone-implant interface. A significant difference was seen between metal injected vs. vehicle control animals and aluminium oxide injected vs. vehicle controls. Particles of stainless steel produced the greatest response and this finding may have implications for the use of metal on metal articulations aimed at eliminating polyethylene wear.

Purpose: With appropriate software, dual energy x-ray absorptiometry (DEXA) provides a means of measuring periprosthetic bone mineral density (BMD) reliably and reproducibly in a single plane. The current method has been improved since the first reports by MacCarthy in 1991.

Material and methods: Since 1992, two series of total hip arthroplasty femoral prostheses using a ceramic-polyethylene cup with a TA6V4 stem were implanted with cement (group A 25 SAS crystal anatomic stems, 22.2 head) or without cement (group B, 27 Euroform stems with hydroxyapatite surfacing on the upper 2/5, 28 head). The patients were followed prospectively with DEXA to measure BMD in the seven Gruen zones immediately after surgery, at six and twelve months, then every year to last follow-up. Mean follow-up was 74 months (36–166). A visual analogue scale was used for subjective assessment of pain. The clinical Harris score and radiological findings were also recorded.

Results: At last follow-up none of the prostheses had required revision surgery. The Harris score was greater than 90 for both groups (mean 91.4 and 95.4 for groups A and B respectively). Radiologically, there were no progressive lucent lines in the two groups but there were three stable lines (zone V, VII, VII, II) without clinical expression in group A and two (zone II, I) with persistent thigh pain in group B. Two migrations of less than 3 mm were also found in group A and four of more than 3 mm in group B. For the two groups, DEXA showed a diffuse reduction in BMD during the first six months that was statistically significant only for zones I and VII for the Euroform implant and for zone VII for the SAS Crystal implant. There was also a significant difference between the two prostheses for zone I. Modifications were not significant at three years and a last follow-up for the distal regions (II, II, V, VI). For group A (SAS Crystal), the reduction was 5.8% at three years and 5.7% at last follow-up for zone I and 18% at three years and 19% at last follow-up for zone VII. For group B, the reduction was 12.6 at three years and 11.4% at last follow-up for zone I and 17.4% at three years and 21.3% at last follow-up for zone VII.

Discussion: The correlations showed that variations in BMD were independent of the initial bone mineral content, patient age or sex, and were not significantly different between the two cemented or non-cemented implants. Patients with painful thighs (two in group A and six in group B) had a different pattern of BMD over time, showing less pronounced reduction in the proximal zones I and VII and marked bone resorption in zones III and V, an expression of different stress transmission.

Conclusion: This study provided the longest longitudinal radiological and clinical follow-up reported in the literature which, despite the bias introduced by the different types of implants, shows the reliability and reproducibility of DEXA of periprosthetic bone mineral density used to assess implant tolerance and quality of cementing.

Unicompartmental knee arthroplasty has been in use since the 1970s. In spite of early enthusiasm, the procedure soon fell into disfavour, particularly in the USA. Early failures were a result of improper indication, poor technique and in some cases and poor prosthetic design.

A new instrument system for use with the MG unicompartmental knee arthroplasty has been designed, with guides for accurate and reproducible alignment, sizing and resection. Potential benefits include early mobilisation, rapid rehabilitation, improved range of motion and shortened hospital stay.

This paper briefly reviews the literature and discusses indications and surgical techniques.

Purpose of the study: Surgical treatment of degenerative spondylolisthesis generally requires spinal fusion. Arthrodesis can be achieved via an anterior or posterior approach. Over the last ten years, minimally invasive methods have been developed to limit operative trauma secondary to the anterior approach. There have however been few studies comparing outcome after this new technique with classical open surgery. The aim of this work was to compare spinal fusion achieved with a cage implanted retroperitoneoscopically with conventional screw-plate fixation using open lombotomy.

Material and methods: Sixty two patients with degenerative spondylolisthesis (L3-L4, L4-L5, L5-S1) were reviewed: 39 had had conventional spinal fusion (group 1) and 23 had undergone a minimally invasive procedure (group 2). Clinical (Beaujon score) and radiographic assessment was recorded at last follow-up. All patients in group 1 were operated on by the same surgeon via lombotomy (L3-L4 or L4-L5 fusion) or subumbilical laparotomy (L5-S1 fusion). An intersomatic graft was combined with screw-plate fixation in all cases. Patients in group 2 were also operated on by the same surgeon (different from group 1) who used a retroperitoneoscopic approach (L3-L4 or L4-L5 fusion). An intersomatic cage was filled with cancelous bone and screwed into the intersomatic space.

Results: Mean follow-up was four years in group 1 and two years in group 2. Mean Beaujon score improved from 8 to 17 in group 1 and from 9 to 16.5 in group 2. All patients achieved bone healing at last follow-up without secondary displacement or disassembly of the osteosynthesis. There were no neurological complications and no infections of the operative site. One patient in group 2 developed a vascular complication requiring conversion to classical lombotomy. Blood loss was 1100 ml in group 1 and 200 ml in group 2.

Conclusion: Anterior fusion with implantation of an intersomatic cage via retroperitoneoscopic access is a reliable and effective method for the treatment of degenerative spondylolisthesis. It reduced postoperative morbidity but must obviously comply with classical indications for lumbar fusion.

Purpose of the study: The principal aim of this prospective multicentric observational study was to validate an self-administered questionnaire for evaluation of functional outcome after surgical treatment of lumbar stenosis. The questionnaire was associated with an index of neurological impairment in order to account for objective neurological injury and an index exploring patient satisfaction after treatment for lumbalgia, radiculalgia and gait disorders.

Material and methods: The structure of the questionnaire was examined to determine whether the three dimensions of the evaluation scale were pertinent, to establish reproducibility (intra-observer variability), to study sensitivity to change, and finally to examine the items in the questionnaire and their capacity for effective measurement using the Cronbach alpha coefficient and principal components analysis. Reproducibility was tested on 49 patients who filled out the self-administered questionnaire twice, 15 days apart. The intra-class coefficients of correlation were calculated. Sensitivity was tested by correlating the variations of the scores obtained pre- and postoperatively with the index of satisfaction and by calculating mean standardised responses. The questionnaire items were validated by correlating the scores obtained using the questionnaire with scores obtained with three other self-administered questionnaires: SF36, EIFFEL2 and GHQ28.

Results: One hundred four patients were included in this study, 96 were seen at follow-up visits six and twelve months after surgery. Principal component analysis demonstrated the pertinence of the three dimensions in the evaluation scale. The overall Cronback alpha was 0.86. The overall intra-class coefficient of correlation was 0.95, varying from 0.86 to 0.97 for the dimensions studied. There was a good correlation (0.82) between the scores obtained and index of satisfaction. All mean standardised responses were greater than A1, indicating good sensitivity to change. There was a good correlation between the evaluated score and the EIFFEL2 self-administered questionnaire and the following dimensions of the SF36: physical activity, physical pain, vitality and limitation due to physical pain.

Discussion and conclusion: Using a simple self-administered questionnaire (eight questions), an index of satisfaction (four questions) and an objective score of neurological disorders allowed reliable, sensitive and reproducible assessment of the changes in the functional impairment caused by lumbar stenosis before and after surgical treatment.

We review our first 100 LCS rotating platform total knee arthroplasty (TKA) procedures. Done between July 1993 and December 1996, they are currently at four to seven year follow-up.

The sample includes 100 TKAs done in 88 patients as unilateral or bilateral procedures. At operation the mean age of patients, 51% of whom were female and 49% male, was 67 years (47 to 84). The right side was replaced in 54% of cases and the left in 46%. Preoperative diagnoses included degenerative and post-traumatic osteoarthritis in 95 knees and rheumatoid arthritis in five.

Two assessments are currently being carried out. They include the American Knee Society Clinical Rating Score, functional ability and radiographic evaluation of knee alignment and radiolucencies. Mean clinical and functional Knee Society ratings were 38 and 57 (sum 95 points) preoperatively and 88 and 84 (sum 172 points) postoperatively. Radiographs showed valgus alignment in 90 rays and varus alignment (1° to 7°) in 10. Limited areas of radiolucency were seen around three tibial components. Two cases have required revision, one for septic loosening and one to correct recurrent varus deformity.

Purpose: The Less Invasive Stabilisation System (LISS) for fixation of the proximal femur is an automatic preformed fixator with three sizes. The self-perforating self-threading screws are locked into the plate fixator providing angular stability. Unlike conventional implants, the LISS plate is not applied directly to the bone, avoiding friction forces and periosteal damage. Precise adaptation of the implant to the form of the bone is not necessary. The system can also be easily and rapidly used as a “gliding” plate. After reduction via a proximal incision, the plate-fixator is inserted between the anterior tibial muscle and the periosteum and fixed with monocortical screws inserted percutaneously.

Material and methods: Between January 1999 and August 2000, we treated 18 multiple trauma patients with fractures of the proximal femur in 17 patients (nine men and eight women) using the LISS in a prospective multicentric study. Mean age was 50 years (20–89), median, 43 years). The AO classification of the fractures was four type A, four type B, and 13 type C. There were 14 open fractures. We used the LISS in one patient to stabilise a valgus osteotomy. One patient had a 41-C2.3 (Schatzker type VI) fracture with a compartment syndrome. Bone allographs were used in two cases. Clinical and radiographic follow-up data was collected at 6, 12, 24 and 48 weeks.

Results: Two foreign subjects with 41-A3 and 41-B1 fractures were lost to follow-up. For the other patients, bone healing was achieved between six and twelve weeks. Mean follow-up was ten months (three to twenty months). We had one complication, the compartment syndrome mentioned above, which healed without sequelae after fasciotomy and secondary thin skin graft. Joint motion was symmetrical and pain free in all patients three months after surgery. There were no nerve or vessel lesions secondary to epiperiosteal displacement of the fixator, and no case of infection or loosening. We did however observe secondary loss of reduction with development of minimal varus in three patients with complex fractures.

Conclusions: These preliminary results with the LISS demonstrate its usefulness as an alternative to conventional fixation systems. It is undoubtedly a most useful method for intra-articular and metaphyseal fractures with diaphyseal fracture lines and for fractures with two levels. Complications appear to depend on the type of fracture and the quality of the reduction, as with other types of fixators.

Purpose: Since the introduction of spinal cord stimulation for the treatment of chronic neuropathies (Shealy, 1967), further development has identified indications. The objective of this prospective multicentric protocol was to quantify clinical and economical results in a homogeneous group of rigorously selected patients.

Material and methods: In 1999, nine university hospital centres recruited 43 patients (22 men, 21 women, mean age 50.8 years) with chronic postoperative neuropathic sciataligia insufficiently controlled by antiseizure and antidepressor (tricyclic) drugs. There were 34 unilateral cases and nine bilateral cases and 60% of the patients also had lombalgia. Diagnosis was established on the basis of history taking, clinical signs, and anatomic and electrophysiological findings. Indications for spinal cord stimulation were determined in a pluridisciplinary context including a psychological evaluation. A temporary test was made before implanting the programmable neurostimulator (Itrel®II or Itrel®3, Medtonic) in order to check that the induced paresthesia involved the painful territory. Included patients were assessed before implantation then at six (39 patients), 12 (30 patients) and 24 months after institution of the stimulation. At each follow-up visit, the clinical effect was assessed with validated pain scales (visual analogue scale, McGill Pain score, Oswestry incapacity score). Economical data were obtained from the medical file, patient interviews, and a specific therapeutic follow-up chart. Preliminary results (mean follow-up 10 months) are presented.

Results: Clinical scores improved 40 to 50% one year after implantation of the neurostimulator. There was significant relief of sciatalgia: on the visual analogue scale the mean pain score (7.8/10 before implantation) was 2.7/10 (p < 0.05) and 3.6/10 (p < 0.05) at six and 12 months after implantation. Drug prescriptions (antiseizure, antidepressors) were reduced by 70%. Residual treatments were prescribed for lumbalgia which was relieved little by stimulation. Annual expenditures (drugs + visits + non-drug treatments) was reduced by 1578 euros per patient (mean). Hospitalisation rate fell from 26% to 10% and the rate of resumed occupational activities was 11%

Discussion: Assessment of 24 patients after implantation of a neurostimulator will complete these early results.

Purpose: Good functional results for unstable fractures of the pelvis require reduction and fixation of the posterior lesions. “Open” techniques are highly invasive and sacroiliac screwing is insufficient alone. We evaluated results with a strategy based on minimally invasive complete reduction and osteosynthesis allowing early mobilisation.

Material and methods: The series included 19 men and two women, mean age 30 years (17–60) operated on between 1998 and 2000. Nineteen patients had multiple injuries. The AO classification was A5 C (12 CI unilateral, 3 (2 C2, 1C3) bilateral) and 6B (4 B1, 3 B2). The patients were operated on in the supine position with traction on the lower limb to reduce the hemipelvis ascension. Displaced anterior fractures were reduced and stabilised with a pubic plate or with an anterior external fixator. The posterior fractures were fixed with a percutaneosus canulated cancellous screw measuring 7.3 mm in diameter inserted transacrally into the S1 body to reach the opposite sacroiliac joint under fluoroscopic monitoring. The radiographic results were analysed by measuring the vertical ascension of the hemipelvis at the foot of the sacroiliac and clinical results with the Majeed score.

Results: The patients were operated on day four 0–8) after trauma. Anatomic reduction was achieved in 19 cases, with a gap of 5 mm in two cases. Thirteen anterior fixations (eleven plates, two external fixators) and 21 transacral screw fixations were used to stabilise the pelvi. There were no notable complications. One patient died early from multiple injuries. All were followed for one year after the accident and no secondary dismanteling has been observed. The final mean Majeed score was 95/100.

Discussion: Reduction is best if achieved early. With the transacral screw fixation, it is achieved in the supine position which is technically difficult due to the known anatomic variability of the sacrum. It also allows simultaneous treatment of C13 and C23 comminutive fractures. Anterior fixation is complete.

Conclusions: Percutaneous transacral screw fixation and anterior osteosynthesis is a minimaly invasive technique providing reproducible and reliable results for maintaining reduction in a large number of unstable fractures of the pelvic ring. These fixations allow the upright position and mobilisation early. The good anatomic result is maintained leading to a better functional result which should be validated in a longer series.

This study examines patient characteristics, indications for conversion, surgical and anaesthetic technique, peri-operative management and complications of surgery in this small and challenging group of patients. In the six years from 1994 to 1999, 33 conversion arthroplasties were performed for failed femoral hemiarthroplasty. The average age at conversion surgery was 75.5 years (range 65–90). The female to male ratio was 6:1. Primary hemiarthroplasties comprised 24 Austin-Moore, 6 Thompson & 3 Bipolar prostheses. The average interval from primary to conversion surgery was 50 months (6 months to 17 years). The average age at primary surgery was 71.2 years (62–88) – AMP:71.4 years, Thompson’s: 74.2 years, Bipolar: 63.5 years. All hemiarthroplasties were performed for fractured femoral necks. 62% of patients came from the Eastern Health Board area, while 38% were tertiary are referrals from other Health Boards. The average length of stay was 17.5 days (3–24). Indications for conversion included gross loosening/acetabular erosion in 9 cases, suspected infection in 4 cases and abscess/septicaemia in 1 case. All but 3 patients had significant pain (night pain etc.) and/or severely impaired mobility.

We also looked at anaesthetic and analgesic practice, surgical technique and prostheses used.

Post-operatively, mean total blood loss was 1430 ml (420–2280) with an average of 1.4 units of blood transfused (0–5). Intraoperative complications included acetabular & femoral perforation, periprosthetic fracture and cement reactions. Complications post-op (in hospital) included cardiac arrhythmia’s, cerebrovascular accidents, pulmonary embolus, myocardial infarct, respiratory & urinary tract infections, constipation, nausea & vomiting.

The elderly nature of these patients and the physiological stress of what is major surgery allied with multiple co-morbidities make their care especially challenging. A conversion arthroplasty is a procedure with a significant risk of considerable morbidity. Primary total hip replacement or bipolar hemiarthroplasty are options which, therefore, should be seriously considered in the case of fractured femoral necks to minimise the need for further surgery in the future, with all its attendant risks.

The posterior ligament complex (PLC) in the cervical spine comprises the posterior longitudinal ligament, ligamentum flavum and ligamentum nuchae, the latter homologous with the supraspinous and interspinous ligaments at other levels of the spine. In determining instability, evaluation of the PLC is an essential part of the assessment of cervical spine injuries. Disruption of the PLC occurs following flexion injuries, both in compression and in distraction, and following extension injuries with compression. PLC disruption, diagnosed when clinical examination reveals localised posterior spinal tenderness and/or a widened interspinous gap, is confirmed on standard and dynamic flexion-extension radiographs and MRI.

This paper is a retrospective review of 162 patients treated for cervical injuries between 1997 and 2001. There were 83 (51%) distraction flexion, 37 (23%) compression flexion, 18 (11%) compression extension, 17 (10%) vertical compression, six (4%) distraction extension and one (1%) lateral flexion injuries. In 79 patients with pure ligamentous instability, an interspinous stabilisation procedure was performed, using a titanium cable. When associated fractures occurred with PLC disruption, neurologically intact patients were managed conservatively with traction followed by a spinal brace. Patients with a neurological deficit underwent surgery. Using delayed dynamic flexion-extension views and MRI, PLC disruption was diagnosed late in nine flexion distraction injuries without facet dislocation. At follow-up, flexion-extension views showed that all PLC disruptions with associated fractures had stabilised. There were two broken cables in patients who underwent surgery.

Patients with cervical instability following trauma may be treated non-operatively when there are associated fractures, while patients with pure ligamentous instability should undergo fusion. Further, to exclude occult PLC disruption, all cervical injuries should be reviewed on flexion-extension views once the paraspinal muscle spasm has settled.

Thoracic spine fractures and fracture dislocations often lead to neurological deficit, and associated injuries to morbidity and mortality.

An audit conducted between January 1999 and December 2000 evaluated the outcome of 63 patients with fractures and fracture dislocations of the thoracic spine. The mean age of patients, 41 of whom were male, was 30 years. In 45 patients the injury was sustained in a motor vehicle accident, and 23 patients had associated injuries. We used the Margel radiological classification. There were 37 fracture dislocations and 23 pure fractures. Twenty patients had a type-A injury (flexion), of which 19 were type AIII (burst). There were 40 patients with a type-B injury, 35 of which were type BI (flexion distraction), and three type BIII (flexion and axial loading). In three patients there was a type-C injury (rotational). There was total neurological deficit in 39 patients, 10 with type-A, 26 with type-B and three with type-C injuries. Fifteen patients had partial neurological deficit and nine were neurologically intact.

Posterior spinal fusion and bone graft was performed on 43 patients, anterior decompression and bone graft without instrumentation on seven, and combined anterior and posterior surgery on one. The remaining 12 were treated conservatively with orthoses. The neurological status of eight patients improved by a single grade following surgery and the neurological status of two following conservative treatment. Of the 54 patients with neurological deficit, 52 were wheelchair-bound. The poor neurological outcome was comparable to that in other studies.

Purpose of the study: Chordoma is a malignant neoplasm believed to arise from notochord remnants. It accounts for approximately 3 to 4 p. 100 of primary bone tumors and is localized along the axial skeleton, 50 p. 100 being sacrococcygeal. Clinical, radiographical and histological findings have been well established since the first description by Ribbert in 1894. Sacral chordomas are however difficult to manage and remain a challenge for surgeons and radiotherapists alike. The purpose of this study was to evaluate the long-term results of surgical treatment and patterns of failure in patients treated for chordoma of the sacrum in our department.

Materials and methods: This retrospective study included 11 cases of sacral chordomas treated from 1973 to 1998. Patient age ranged from 36 to 77 years (mean 59 years). Six patients were female and five male. The initial treatment was surgery in all cases including intralesional removal in two cases, marginal resection in seven and complete en bloc resection in two.

Results: Median follow-up was 6 years (1 month to 14 years). Tumoral recurrences were observed in nine cases 5 months to 8 years after treatment. In two cases, recurrence was observed 8 years after radical sacrectomy. Treatment of recurrences was partial surgical removal with radiotherapy (40 to 70 Grays). Three patients developed metastases in lungs, liver and bone, respectively. Seven patients died, two from metastatic disease. The 5-year overall survival was 64 p. 100 but only 18 p. 100 of the patients survived 10 years. Average disease-free survival was 18 p. 100 at 5 years and 0 p. 100 at 10 years.

Discussion: Chordoma is a slow-growing tumor allowing survival for several years despite recurrent disease. However, only 10 to 20 p. 100 of the patients survive free of disease at 5 years. Recurrences are frequent (45 to 80 p. 100) and often multiple. Chordoma inevitably recurs and eventually leads to death after intralesional removal or marginal resection. Radical surgery should be attempted whenever technically feasible. When performed early, particularly for smaller lesions, it offers the best chance for cure. However, tumoral recurrence can occur postoperatively despite a macroscopically complete resection. Because radiation therapy seems to be more successful in controlling microscopic disease, it should be considered as a pre- or postoperative adjuvant to a macroscopically complete resection.

The intermetatarsal angle is widely used to determine whether a basal or distal metatarsal osteotomy should be used to correct a hallux valgus deformity. We have noticed that the point of intersection of the long axes of the first and second metatarsals on standard pre-operative weight-bearing AP radiographs consistently predicts the type of osteotomy required.

A basal osteotomy is generally recommended if the inter-metatarsal angle is ≥14°, whereas a distal osteotomy is usually sufficient if the angle is less than 14°.

Sixty standardised pre-operative AP weight bearing in-patients undergoing hallux valgus correction were included in our study. The intermetatarsal angle was measured in a standard fashion. The point of intersection in the foot was recorded in terms of the distance from the talonavicular joint.

Using a Pearson’s Correlation coefficient, our study revealed that an intermetatarsal angle of 14° or more consistently intersected either within the talar head or distal to thetalonavicular joint. We propose that this as an accurate and simple method of pre-operatively determining the choice of metatarsal osteotomy.

Dislocations of the thoracolumbar spine, which account for 11% of injuries in the T10 to L2 region, follow a high-energy, flexion-distraction force. In this region, there is a transition from a fixed kyphosis to a mobile lordosis, an absence of costotransverse ligaments and a change of facet alignment from a coronal to a sagittal plane.

In 1999, we treated 12 male and nine female patients with dislocations of the thoracolumbar spine. Their mean age was 30 years. Sixteen patients had been involved in motor vehicle collisions, four had fallen from a height and one had been assaulted with an iron bar. There were 14 Frankel grade-A injuries, one Frankel grade-C, two Frankel grade-D and four Frankel grade-E injuries. The site of injury was T12/L1 in 14 patients, L1/L2 in four, T11/T12 level in four and T10/T11 in one. Associated injuries included electrical burns and a fractured femur. None of the patients sustained visceral injuries. All patients were stabilised with transpedicular fixation. No disc sequestration was found.

Following surgery, one of the 14 Frankel grade-A patients improved to Frankel grade C but 13 made no neurological recovery. The four patients graded Frankel E did not deteriorate. The remaining three patients with partial neurological deficit made a complete recovery. Postoperative sepsis resolved in one patient following debridement and antibiotic therapy.

The thoracolumbar junction is anatomically and biomechanically predisposed to traumatic dislocation. The poor neurological outcome with dislocations at T11/T12 and T12/L1 may be attributed to cord injury, but injuries distal to this level have a better prognosis owing to cauda equina involvement.

Purpose: We report our experience with 23 Coonrad-Morrey total elbow prostheses.

Material and methods: Between July 1997 and February 2001, we implanted 34 Coonrad-Morrey total elbow pros-theses in 33 patients. Twenty-three patients (23 implants) were reviewed at a mean 24 months follow-up, maximum 40 months. There were three men and 20 women, mean age 62 years (42–69). Twelve patients had rheumatoid polyarthritis, the principal indication. There were also four recent fractures of the distal humerus, two nonunions, and one patient with post-traumatic osteoarthritis. One patient had sequelar osteoarthritis since childhood. Finally three revisions were performed for loosening of a GUEPAR prosthesis in two cases and a GSBIII prosthesis in one. Results were assessed with the Mayo Clinic score. We searched for lucent lines around the implants, polyethylene wear, and incorporation of the bone graft behind the anterior wing of the implant on plain radiographs.

Results: At last follow-up, the mean Mayo Clinic score had improved from 25 to 89 points (70–100). Before surgery, 17 patients had severe pain. At last follow-up, eight patients had occasional pain. Extension was improved by 10°, flexion by 27° giving a postoperative amplitude of 29° to 132°. Prona-tion supination progressed by 37° giving a rotation amplitude of 127°. The function score improved from 4 to 21 points. Sixteen of the 23 patients had normal elbow function. Outcome was excellent in 13 patients, good in eight, and fair in two. There were no lucent lines visible on the radiographs. There was no sign of polyethylene wear. The bon graft was incorporated behind the implant in 20 cases and was not visible in three. Complications included one peroperative fracture, one cutaneous dehiscence, one post-operative fracture of the olecranon due to a fall, and persistent ulnar paresthesia in four patients requiring secondary neurolysis in one.

Discussion, conclusion: The Coonrad-Morrey semi-constrained prosthesis provides a response to a large range of situations. The dominant indication is rheumatoid polyarthritis, but trauma patients can benefit from this reliable therapeutic solution giving a satisfactory rate of success. A satisfactory functional amplitude is generally achieved with this implant and the elbow is generally pain free.

Purpose: Traffic accidents and high level falls are the principal causes of femur trauma. Fractures generally involve the shaft but the proximal or distal metaphyseal zones may also be involved. Skin opening, vascular injury or associated lesions in multiple injury patients are all reasons for emergency treatment with an external fixator.

Material and methods: We report a retrospective series of 23 cases who were treated with this technique between 1996 and 2000. There were 15 men and seven women, mean age 36 years (17–92) who were traffic accident victims in 17 cases. Fourteen had multiple injuries. The mean Index Severity Score was 28 points. Fractures were located in shaft in 16 cases, the proximal metaphysis in three, and in the supra and intercondylar zone in nine. The Chauchoix and Duparc classification was grade 2 in eight cases, and grade 3 in three cases. The fixation was installed with two or three pins in the lateral position; The knee was bridged in cases with an associated injury to the proximal tibia (floating knee) (two cases) or severe injury to the knee ligaments. Patients were reviewed clinically and radiographically. Bone healing was considered to be achieved when full weight bearing was possible without osteosynthesis contention.

Results: Twenty patients were reviewed. Mean follow-up was 20 months (7–42). Bone healing was achieved in 100% of the cases with a mean delay of 9.4 months (4–32). In three patients 13%) a complementary procedure (cancellous graft or bone marrow graft) was needed to achieve healing, the delay in these patients was 22 months compared with 7.5 months without secondary procedures. One patient developed a callus with a > 10° deviation of the AP view and five permanent flexion greater than 10°. Supra and intercondylar fractures healed at a mean 6.6 months in five cases with a deformed callus. The force moment related to excessive spread of the fixator pins (greater than 20 cm) was not a factor of poor final radiological outcome. Mean knee flexion was greater than 100° in only three cases. These amplitudes were not obtained until the fixator pins were removed. No releasing procedures were needed. Three mobilisations under general anaesthesia were needed.

Discussion: External fixation allows stable and dynamic osteosynthesis of femoral shaft fractures. It is indicated when centromedulary nailling is impossible or for patients with an excessively high risk of infection. The insertion of the pins must be rigorously control (perpendicular to the diaphysis, bicortical insertion, far enough apart). Supra and intracondylar fractures remain difficult to stabilise with external fixations and internal plate fixation may be discussed in grade 2 open fractures. These can give poor functional results despite rapid consolidation. An immediate corticocancellous graft may be indicated when metaphyseal comminution requires stabilisation, mainly on the medial aspect to avoid varisation.

Conclusion: External fixation is an interesting solution for safe fixation of open shaft fractures (grade 2 and 3) or fractures associated with vascular and nerve injury. It would be more indicated for shaft fractures than for supracondylar fractures which are difficult to stabilise, particularly in case of major comminution.

There is a desire to reduce the economic burden of low back pain. This in is part because of the 226% increase in invalidity benefits paid out for spinal disorders in the ten years to 1994/5. This paper examines the effect of the change from Invalidity Benefit to Incapacity Benefit in 1995, and considers the utility of these figures as a means of assessing changing patterns of back pain disability.

Data were obtained from the DSS on how benefit data were collected and numbers of days of Invalidity/Incapacity Benefits that were paid from 1983/4 to 1998/9. The data suggest that since 1995 that the rate of spinal disability has fallen and has now been stable at 90 million days per year for four years. The headline Incapacity Benefit figures have a very loose relationship with health impact of low back pain. Around 30,000 people per year make the transition to claiming long term Incapacity Benefit from claiming short term Incapacity Benefit.

Incapacity Benefit figures are of little utility in assessing changes in low back pain disability. Numbers making the transition to Long Term Incapacity Benefit may be a more useful indicator.

Evaluating the effectiveness of conservative treatment of odontoid fractures, from 1997 to 1999 we reviewed 22 cases.

All were treated first in halo traction and subsequently by halo thoracic brace immobilisation. We used Anderson and D’Alonzo’s classification of types I to III. The mean follow-up time was seven months. Initial displacement was measured radiologically and union was evaluated.

In type-II fractures, the incidence of pseudarthrosis was 40%. Fractures with more than 5 mm of initial displacement and more than 10° angulation all went on to nonunion, suggesting that type-II fractures should be treated by internal fixation.

Purpose: Trauma to the radial collateral ligaments requires the same attention as trauma to the ulnar ligaments. Damage is uncommon due to the particular anatomic position, but nevertheless a distinct clinical entity.

Material and methods: We report a retrospective analysis of 14 patients, eight who underwent emergency surgery and six with trauma sequelae. Mean follow-up was 22 months and mean age 37 years. Among the recent lesions, the pain score (scale from 1 to 5) was 4.5) and the instability score (scale from 1 to 3) was 3. Palmar subdislocation was 4.8 mm and laxity was 16.7°. Among the old lesions (> 1 month) the corresponding data were pain 3.3, instability 2.5, palmar sub-dislocation 4.2 mm, laxity 19.1°. Two patients had signs of osteoarthritis. At surgery, the phalanx and metacarpus were equally injured. Associated lesions (capsule, short abductor) were present in 78% of the patient. The radial collateral ligaments and the soft tissue were reinserted or retightened in all cases. One patients required arthrodesis due to cartilage damage.

Results: Among the recent injuries, 71% reached a good subjective result: amplitude loss (flexion/extension) was 17°, force was 75% and laxity was 5°. Two patients had palmar subdisloction. Among the older lesions, a good subjective result was achieved in 66%: loss of amplitude case 32°, force was 69% and laxity was 8°. Palmar subdislocation was 2 mm on the average. We had two cases of persistent dysaesthesia.

Discussion: Radial injury appears to be falsely benign because the Stener lesion is not found on this side of the metacarpophalange. The importance of the injury in these traumas is related to the vulnerability of the dorsal region of the medial collateral ligament and is probably the cause of poor outcome after surgery for older lesions with palmar dislocation which is difficult to correct. We advocate emergency surgery for a wide range of indications. We always operate major radial laxity (> 35°) or laxity associated with palmar subdislocation. For other cases, we use the anterior forced drawer view to disclose potential associated dorsal injury.

Purpose: The purpose of this study was to: 1) analyse sequelae after fracture of the lateral process of the talus (deformed callus or nonunion) in six patients included five who were operated, the impact on the talocrural and subtalar joint, and treatments that can be proposed and expected results; 2) emphasise the fact that this lesion is not often recognised in its initial stage, leading to late diagnosis despite the better results obtained with early treatment.

Material and methods: Six patients were seen at consultation at the sequelar stage. There were six men, mean age 40 year (20–60); three were high-level athletes. The injury was cause by fall from a high level, two accidents leading to multiple injuries with an unanalysable mechanism, and ankle “sprain” in one patient. Delay to therapeutic management was four months to ten years (mean two years). Pain and joint stiffeness involving the talocrural joints and/or subtalar joints were the predominant signs. The deformed calluses involved the subtalar joint in five cases with one case of nonunion. Five of the patients had been treated surgically: four resections, one screw fixation of the nonunion, and one patient desired surgery. In all the operated cases, pain had disappeared almost entirely but the amplitude of the joints was not totally recovered.

Discussion: Two aspects are particularly important. first fractures of the lateral process of the talus must be considered globally. Frequency has been estimated at 1% of all ankle trauma, certainly an underestimation since these fractures often go unrecognised in the early stages and are too often confused with ankle sprains. Incidence is also increasing with the practise of snow boarding where this injury occurs in 15% of all ankle traumas. The injury results from distraction via the talocalaneal ligaments in an inversion trauma or by compression during dorsiflexion and pronation. Clinical diagnosis is difficult and plain x-rays poorly visualise the lesion, irrespective of the anatomic type (MacCrory classification). CT scan is required to obtain an exact analysis of the fracture and its displacement, necessary for correct treatment: simple immobilisation if there is no displacement or resection of the fragment or osteosynthesis depending on the size of the fragment. Secondly, the pathology of this injury is important to recall: deformed callus or nonunion. The volume of the lesion and its site explain the observed impact, but in all cases, the injury involves the talocruaral joint (painful impingement of the fibular ligament) and talar disorganisation (pain, stiffness or osteoarthritis at the later stages). Depending on the case, treatment consists in excision of the deformed callus, fixation of the nonunion and, for cases seen late, subtalar arthrodesis. An improvment in pain can be achieved but there is almost always loss of joint amplitude.

Conclusion: Whatever treatment is used, the results at the sequelar stage are never excellent. Only early diagnosis with a rigorous clinical examination and adapted imaging (CT scan) can lead to coherent early treatment which provides the best result.

Two calcium phosphate cements, brushite and hydroxyapatite, have been recently developed as bone substitution materials. The brushite cement is biocompatible, resorbable, osteoconductive and injectable since it hardens in physiological conditions. In contrast, hydroxyapatite is less resorbable and is not injectable. However, hydroxyapatite presents a higher strength, which may open the perspective of use in weight-bearing regions of the skeleton subjected to multi-axial stresses. The purpose of this work is a full characterization of the multiaxial elastic and failure behaviour of these two cements in a moist environment.

The brushite cement was prepared by mixing three phosphate powders in presence of water. A mixture of monetite and calcite powders in presence of water was used to obtain hydroxyapatite self-setting cement. Cylindrical, hollow specimens (Øext=18mm, Øint=14mm, L=40mm) were manufactured to apply uniaxial and torsional deformations. The specimens were cast with a custom mould, avoiding any machining, and thus, residual stresses. Scanning electron microscopy and x-ray diffraction were used to examine the cement microstructures and to determine their final material phases. An MTS axial-torsional machine was used for all mechanical tests. Compression, tension and torsion tests were performed each on five brushite and five hydroxyapatite specimens under moist conditions. Uniaxial and biaxial extensometers were used to measure the elastic moduli and the Poisson ratio.

The brushite cement exhibited failure properties comparable or below those of average human cancellous bone and confirmed its indication as a bone filling material (Brushite failure strength : 1.3±0.3 MPa in tension, 2.9±0.4 MPa in shear and 10.7±2.0 MPa in compression). The hydroxyapatite cement had an order of magnitude larger compressive strength (75±4.2 MPa), comparable tensile (3.5±0.9 MPa) and shear (4.8±0.3 MPa) strengths as average human cancellous bone. As expected, the latter cement seems to be more compatible with a multiaxial weight-bearing function in bone substitution.

Purpose: All displacements can be described with x, y, z coordinates. We propose an anterior view of the first metatarsal associated with a peroperative test to determine the precise position in the frontal plane, both statically and dynamically. Lateral release is an important step in surgical treatment of hallux valgus. Both the extent of release and the potential benefit of no release must be carefully evaluated. We propose a view allowing an assessment of the metatarsophalangeal reducibility.

Material and method: Peroperative test. This test explores cuneometatarsal laxity. We conducted a prospective study in 100 cases. A 12/100 pin was used to immobilise the first cuneiform and a 20/100 pin was placed in the base of the first metatarsal. A third distal pin in the neck was used to pivot the bone on its axis. A small protractor was used to measure the angle by projection with ±2.5° precision.

Modified Guntz view. This is a weight-bearing anterior view of the first metatarsal. The cassette is positioned posteriorly. The patient stands with the heal raised 40 mm on a 20mmx20mm plexiglass bar. The metatarsal diaphysis must appear perfectly vertical. An isosceles triangle is constructed on the articular facets; the base of the triangle is perfectly horizontal and defines the pronation-supination angle. We made 100 measurements and checked correlation with the peroperative test.

Reduction view. A Zimmer brace was used to reduce the varus metatarsus and adduct the toe. The metatarsophalangeal angle and the position of the sesamoids were used to assess reducibility.

Results: Pronation and/or pronation instability was = 10° in 96% of the patients. The reduction view enabled classifiation by three grades of reducibility.

Discussion: Our contribution is determining for correction of displacements taking into account the frontal plane. No other study has shown so clearly the existence of metatarsal pronation. We also confirmed the presence of a large proportion of cuneometatarsal instability. The extent of lateral release or the potential benefit of no release can now be assessed.

Conclusion: A certain number of failures have undoubtedly been related to neglect of the parameters studied here. It is indispensable to explore the frontal plane and the dynamic parameters before establishing indications for new flat-oblique metatarsal osteotomies using conventional or minimally invasive techniques.

Lisfranc injuries make up 0.2% of all fractures. With or without midfoot injuries, treatment requires early accurate diagnosis, anatomical reduction and stable internal fixation. Some surgeons prefer K-wire fixation, while others rely on rigid screw fixation, especially of the medial column. To assess the radiological and functional outcome of K-wire fixation of Lisfranc injuries, we carried out a prospective study between January 1999 and December 2000.

The ages of our 15 male and four female patients ranged from 15 to 47 years. Using the Quenu and Kuss system to classify injuries, we treated five isolated, nine homolateral and five divergent injuries. In eight patients there were associated midfoot injuries, and four had compound fractures. We treated 11 fractures with closed reduction and K-wires. Open reduction with K-wire fixation was carried out on eight fractures, including the four compound fractures, within 19 days of admission. All patients were kept non-weight-bearing in a short backslab, and the wires removed at six weeks. Follow-up times ranged from 4 to 19 months.

To assess functional outcome we used the American Orthopaedic Foot and Ankle Society’s midfoot scoring system, which has a maximum score of 100. The mean score of our patients was 70 (52 to 85). Mild or occasional foot pain and slight gait abnormality resulted in limitation of recreational activities. At three months, 15 patients were fully weight-bearing. A single case of superficial sepsis resolved, and there were no cases of implant failure or loss of reduction.

K-wire fixation following anatomical reduction is a satisfactory option for the treatment of tarsometatarsal injuries, especially when severe injuries involve the midfoot. The technique is minimally invasive and the K-wires are easily inserted and removed.

Purpose: We report a series of 52 chronic Achilles tendinopathies. Surgical treatments included peritendon dissection, release of the fasia cruris, limited blunt combing of the tendon, and resection of nodules, calcifications and cysts as needed.

Material and methods: Mean duration of disease before treatment was 18 months. Twenty-six patients had sports activities. There were 12 bilateral cases. Pain was present in all cases. Ultrasonography was used to establish the PUDDU classification: paratendinitis 21, tendinitis 22, paratendinitis with tendinitis 9. All patients were reviewed at two years. Clinical criteria were used to assess outcome.

Results: Mean follow-up was five years six months. Complete pain relief was achieved in 29 cases. Motion was normal in 48 with recovery of former sports level in 29. Overall outcome was very good in 29, good in 14, fair in six and poor in three.

Discussion: The mean age of patients with poor outcome was relatively high. All the poor results were correlated with amyotrophy. The presence of a foot deformity did not appear to have an unfavourable effect on outcome. Infitration of the Achilles tendon should be avoided. Avoiding immobilisation appears to prevent tibiotalar stiffness. Ultrasonography can distinguish paratendinitis, tendinitis and paratendinitis with tendinitis but MRI offers very precise images of the lesions.

Conclusion: Surgical treatment of chronic Achiles tendinopathy can be proposed after failure of medical treatment. Outcome is better in younger subjects who participate in sports activities and who have paratendinitis.

Introduction: Polyethylene wear can be an important cause of knee replacement failure.

Method: Six TKRs in young, active patients with excellent Oxford Knee Scores and Knee Society Scores, mean 76 months post knee replacement and 5 control patients, 2 weeks post TKR, were selected. Each patient had weight bearing stereo radiographs of at 0, 15, 30, 45 and 60 degrees of flexion while standing in a calibration grid. These x-rays were analysed using our Radio Stereometric Analysis (RSA) system. The three-dimensional shape of the TKR (manufacturer’s computer aided design model) was matched to the TKR silhouette on the calibrated stereo radiographs for each angle of flexion. The relative positions of the femoral and tibial components in space were then determined and the linear and volumetric penetration was calculated using Matlab software.

Results: The accuracy of the system was found to be 0.3mm (CAD model tolerance 0.25mm). The mean linear wear in the control patients was 0.02mm (range −0.19 to +0.23mm). Average linear penetration in the study group was found to be 0.6 mm at 6 years, giving an overall linear wear rate of 0.1mm/year. Average penetration volume at 76 months was 399mm³. The average volumetric wear rate was 63mm³/year.

Conclusion: It is possible to measure volumetric wear in vivo using RSA. Volumetric wear rate was found to be 63mm³ per year. Studies on retrieved normally functioning hip replacements have shown volumetric wear rates of 35mm³ per year. However, clinical outcomes of knee replacements are comparable to those of hip replacements, suggesting that the knee has a more effective mechanism for dealing with polyethylene wear particles.

*Oxford Hip and Knee Group: P McLardy-Smith, C Dodd, D Murray & R Gundle

The objective of our research is to elucidate the pathogenesis of soft-tissue contracture. Here we present a comparison of collagens isolated from deltoid ligament of 23 clubfeet classified according to the Dimeglio-classification and of 14 matched controls of normal feet.

Collagens were isolated by acetic acid extraction and by limited pepsin-solubilisation and analysed by SDS-PAGE. Ligaments and solubilised collagens were analysed for their extent of hydroxylation of prolyl- and lysyl-residues, their content of galactosyl-hydroxylysine and glucosyl-galacto-syl-hydroxylysine and their content of lysyl-oxidase dependent cross-links histidinohydroxylysino-norleucine (HHL), hydroxylysylpyridinoline (HP) and lysylpyridinoline (LP). Analysis were carried out using an amino acid analyser (Bio-chrom 20, Amersham Pharmacia Biotech) and a reverse-phase HPLC system (Gynkothek).

Percentage of collagen of total protein decreases in club-foot as compared to controls. SDS-PAGE of solubilised collagens shows a high content of type I, less of type III and small amounts of type V collagen in both groups. The extent of hydroxylation of proline appears to be very similar, whereas the degree of hydroxylation of lysine follows the Dimeglio-classification. In addition, glycosylation of hydroxylysine increases parallelly to the classification. However, the increase is found solely in the amount of disac-charides. Total content of HHL, the most important collagen cross-link in soft tissues, was increased significantly in club-feet as compared to controls. HP, the hard tissue specific collagen cross-link was increased slightly in clubfeet. Levels of LP were too low to detect differences precisely.

The data presented show distinct differences in the post-translational modifications of collagen (hydroxylation of lysyl-residues, glycosylation and lysyl-oxidase dependent cross-links) isolated from congenital idiopathic clubfeet and from controls.

We retrospectively reviewed 100 consecutive cases of foot trauma, sometimes accompanied by other injuries, in people who had instituted legal proceedings to recoup losses after motor vehicle accidents. To keep matters in their correct perspective, it must be noted that claims on a contingency basis were not acceptable at the time of this review.

We excluded from the study patients with only minor foot injuries and significant other injuries. There was significant foot trauma in 14% of the reviewed motor vehicle accident cases, and 75% of patients had significant other injuries. Of patients who had suffered only foot trauma, 32% were male and 68% female. Their mean age was 36 years and the review was conducted a mean of 28 months after injury. Of those who suffered multiple injuries, 65% were male and 35% female. Their mean age was 34 years and the review conducted a mean of 21 months after injury. Combining the effects of patients’ other injuries but reviewing foot injuries separately, we assessed the long-term impact of the injuries as minimal, slight, moderate, severe or very severe. Nearly 50% of the foot injuries had a severe or very severe long-term impact, involving loss of amenities of life and the ability to earn a living. In 44% of the multiple trauma cases, the foot injury alone would cause significant loss of income. In about 30% of these cases the other injuries would have a similarly negative effect. We estimated that 60% of foot injures and 40% of other injuries would later come to need surgical treatment.

When we assessed the quality of care the patients received, we found that 50% of those with only foot injuries and 40% of those with foot and other injuries had not been given optimal treatment for their foot injuries. In 15% of cases the other injuries could have received better treatment.

Our review showed that foot injuries sustained in motor vehicle accidents can have serious long-term effects. However, because they are not life-threatening, at the time of the accident foot injuries receive suboptimal treatment. In multiple trauma patients, foot injuries should not be overlooked. Optimal treatment will improve the final outcome and enjoyment of life of motor vehicle accident victims.

Purpose: We reviewed major amputations of the lower limbs in geriatric patients.

Material and method: This retrospective study was conducted in patient treated between January 1990 and December 1999. A total of 265 amputations in 209 patients, including 24 revisions and 32 bilateral amputations, were included in the study. Inclusion criteria were the major nature of the amputation requiring prosthetic fitting and patient age (greater than 65 years).

Results: The incidence of amputation in our geriatric population was 4 per 10 000. Mean age at amputation was 78 ± 7.5 years. Mean follow-up was 27.8 months. Tibial amputations predominated (123/264, 46.4%). Aetiology factors were basically diabetes mellitus (99/209, 47.4%), and atherosclerosis (85/209, 40.7%). Overall survival at one year was 61.7%, 47.9% at two years and 13.7% at ten years. Survival was better for tibial amputations (p = 0.023). Analysis of 12 comorbiditties revealed that amputated patients had significantly higher mortality when they also had heart failure (p = 0.001), dialysis (p = 0.001), rhythm disorders (p = 0.003), dementia (p = 0.008). Rhythm disorders (p = 0.01) and dementia (p = à.02) usually predicted a femoral level of amputation. The number of surgical revisions required for amputation at a higher level was 9.1% (24/265). Amputations of the contralateral limb were required in 34/209 patients (16.3%) after a mean delay of 19.7 months. Half of our patients were fitted with a prosthesis (53.6%, 112/209).

Discussion: We did not find any predominant aetiological factors by level of amputation. Statistical analysis demonstrated that survival depended on the low level of the amputation. Preservation of the knee was an important factor not only for rehabilitation but also for mortality. Survival after femoral amputation and after desarticulation of the knee was the same. Prosthesis fitting was difficult at the femoral level. Mortality depends on four basic comorbidities, heart failure, dialysis, rhythm disorders and dementia. Addition of comorbidities for a given patient has a significant effect and is not compatible with survival greater than five years.

Purpose: Retrograde nailing is emerging among methods proposed or stabilisation of femoral fractures above total knee arthroplasties (TKA).

Material and methods. Between June 1994 and may 2000, 12 fractures above TKA were treated by retrograde nailing. These fractures occurred 43 months (4–51) after implantation of the TKA in three men and women aged 74 years (43–88). The fracture was situated just above the prosthetic trochlea in ten, and distant from the implant in two. The posterior cruciate ligament was preserved in six TKA and six were posterior stabilised prostheses. Indications for arthroplasty were degenerative joint disease in nine and rheumatoid polyarthritis in three. Four patients had proximal implants (one fixation and three prostheses). A percutaneous approach was used except for three cases in order protect the tibial component. Closed reduction was achieved, but required an open reduction for completion in two cases. the nail was advanced just to the trochlea in patients with a preserved posterior cruciate ligament and beyond the posterior stabilisation cage for the posterior stabilised implants. The knee was mobilised immediately after surgery and total weight-bearing was encouraged four to six weeks later.

Results: There was one error in the proximal aiming, one metastatic infection from a leg ulcer at three months and one tibial loosening in a polyarthritic woman 66 months after arthroplasty, i.e. 51 months after the fracture. Bone healing was achieved at two to four months. Frontal deviation was less than 5°. Recurvatum was less than 5° in eight cases, between 5° and 10° in two cases and between 10° and 20° in two others. At mean follow-up of 23 months (3–60), maximal moss of mobility was 10°. There was not worsening of pain.

Discussion: Retrograde nailing leads to bone healing with satisfactory frontal alignment and minimal loss of mobility. The approach uses the initial incision, facilitating complementary procedures or revision if needed. The main problem is controlling recurvatum, even though at the follow-up reported there was no clinical impact or loosening. The limitations of this method are well defined: free medullary canal, sufficient knee flexion, compatible femoral component. The tibial obstacle in posterior stabilised implants is less well known; It should be protected during the nailing if it is high. The polyethylene insert may have to be removed temporarily in certain cases.

Conclusion: The two principal problems with retrograde nailing are recognising implants compatible with this technique and controlling recurvatum. Results are acceptable with a minimally invasive technique.

The aim of this study was to compare implementation of RCGP guidelines in patients in Primary Care with acute low back pain between GP and Nurse Practitioner. This report presents preliminary results.

The intention was to recruit 200 patients presenting to GP with new episode of back pain. 50% randomised to NP care, 50% to GP care. Outcome measured by documentation audit and patient feedback. Individuals complete a questionnaire which includes a Low Back Outcome Score (LBOS) at 14 weeks, 6,12 and 24 months. All patients in NP arm given back book and advised against bed rest.

Initial Findings: (n = 145): The LBOS score was identical (30) for the 73 patients randomised to nurse practitioner care and the 72 with routine GP care. There were no significant differences between the scores at 14 weeks and 6 months, with an increase in LBOS to 45–49, but numbers dropping to 28 in the NP group and 26 in the GP group.

Process audit at 14 weeks: Only 10 of NP patients were not given the back book compared with 74% for GP care. 13% of NP patients were prescribed bed rest against 18 for GP care.

Initial results suggest no significant difference in outcome between GP and Nurse Practitioner patients. Of interest is that 10% and 13% of patients failed to recall important features of management. This implies that audit of healthcare processes by patient questionnaire may be unsatisfactory.

Thromboembolism is a potentially fatal complication of total joint replacement. Some surgeons follow a ‘prophylaxis without compromise’ policy, while others, who realise that there are risks attached to the use of prophylactic drugs, go to the opposite extreme and administer no prophylaxis and no anti-thrombotic drugs, even for pulmonary embolism.

We believe the results of surveillance should determine the administration of anticoagulation therapy. In over 1 500 patients, anticoagulants have been administered only when clinically indicated and after positive Duplex diagnosis. Death due to pulmonary embolism has occurred in only two patients in six years, a reduction from 1.0% to less than 0.05%.

Our treatment protocol divides our patients into high and low risk cases. The results of Doppler and blood tests dictate the method and extent of prophylaxis for high-risk cases, and the therapeutic handling of positive clot formation in the low-risk population.

General Practitioner (GP) attendances for non-specific disease increase after life events. Whiplash injury has the effect of a life event in some people.

The aim of this study was to compare GP attendance rates in the year before and after whiplash injury to establish their rate and cause.

Ninety-eight subjects (62 women and 36 men) with whiplash injuries examined for medicolegal reports, with complete GP records for a year before and after injury.

The number of attendances and the reason for attendance. Consultations after the accident were subdivided into those for neck pain and for other reasons.

Subjects were reviewed more than one year after injury. All described neck pain 11% mild, 62% moderate and 27% severe. GP attendance rates before the accident were within the normal range but increased after (p=0.0001) because of neck pain symptoms. There was no association between attendance rates before and after injury but consultations for neck pain rose in proportion to severity of symptoms (p = 0.0015). Attendances unrelated to neck symptoms fell after injury (p = 0.002).

GP attendances for non-specific disorders increase after life events, but not after whiplash injury as patients focus on their neck symptoms.

Purpose of the study: The aim of this study was to evaluate the anatomical and technical limits of endoscopic rotator cuff repair. Anatomical results were also compared with functional assessment of the shoulder.

Material and methods: A multicentric serie of 87 patients presenting a full thickness rotator cuff tear repaired endoscopically was retrospectively reviewed at 25.4 months (mean) post surgery. Limits of the surgical technique were studied in correlation with functional results and anatomic radiographic evaluation (arthroscans in 93 p. 100).

Results: Anatomical repair (normal thickness and no contrast in the subacromial space on arthroscan) was achieved in 83 p. 100 of the rotator cuffs with limited damage to the frontal part of the supra spinatus tendon. This percentage fell to 57.8 p. 100 in case of posterior extension of the tear to the supra spinatus tendon and further dropped to 40.8 p. 100 in case of retraction to the apex of the humeral head. Functional outcome evaluated with the Constant score was strongly related to the radiographic cuff condition (p < 0.05). For distal and anterior tears of the supra spinatus tendon, the Constant score at revision was 89.8 points in cases with anatomic repair at revision. This score fell to 75 when the rotator cuff tear was evidenced radiographically (p < 0.0001). For tears involving the entire supra spinatus tendon repaired by arthroscopy, the functional difference at revision was 8 points on the Constant scale. Objective and subjective analysis of the surgical procedure identified significant peroperative elements predictive of clinical and anatomical outcome (difficult reduction, p < 0.05; subjective degree of solidity, p < 0.0001; anatomical aspect of the repaired cuff, p < 0.05).

Discussion: A comparison of our findings with data on equivalent lesions reported in the literature suggests that endoscopic surgery for rotator cuff tears offers both functional and anatomic results equivalent to those achieved with conventional open surgery. This assumes that the surgical procedure is carried out by surgeons experienced in shoulder arthroscopy who can precisely gauge the posterior/anterior extension of the tears and the limits of the surgical technique.

The majority of studies investigating the outcome of lumbar decompression surgery have been retrospective in nature and have not used validated measures of outcome. The aim of this study was to prospectively investigate the short and long term outcome of lumbar decompression surgery in terms of function, disability, general health and psychological well being.

Eighty-four patients undergoing lumbar spinal stenosis surgery were recruited into this study. Patients were assessed using validated measures of outcome pre-operatively, and at 6 weeks, 6 months and one year post-operatively.

A significant reduction in pain (p< 0.001) was observed at the 6 week post-operative stage, this did not change at the subsequent assessment stages. Only some of the SF~36 categories were sensitive to change. The sub-categories that were sensitive to change were; physical function (p< 0.05); bodily pain (p< 0.001); and social function (p< 0.05). Improvements were observed in these categories at the 6 week and 6 month reviews. A gradual reduction in the Oswestry Disability Index (ODI) was observed with time, with changes principally being observed between the 6 week and 6 month review, and 6 week and one year review stages (p< 0.05). Minimal changes were observed in the psychological assessments with time. The outcome of surgery could not be predicted reliably from psychological, functional or pain measures.

Lumbar decompression surgery leads to a reduction in pain and some improvements in function.

Purpose: The aim of this work was to evaluate the short- and long-term biocompatibility, tolerance and tissue response after implantation of an intersomatic bioresorbabled lumbar cage (Phusiline®).

Material and methods: Eighteen sheep were operated on in 1999; three animals were sacrificed for study at three, six, nine and twelve months after implantation. The cage was placed between two lumbar vertebrae and filled and covered with cancellous bone. Cerebrospinal fluid, lateroaortic lymph nodes, liver, spleen and kidney samples were taken after sacrifice. The spinal segment from L1 to S1 was removed with the surrounding ligaments and muscles for radiography, MRI, and CT scan. Histology sections were stained with Paragon. The pathology examination included: bone and cell density, degree of tissue differentiation in contact with the implant, remodeling and consolidation of the fusion, implant resorption and associated reactions. An epifluorescence study was performed to assess bone apposition. Reaction of tissue in contact with the implant or far from the implant (laterovertebral muscles, paravetebral lymph nodes, liver, kidney, spleen) were qualified histologically.

Results: At three months, there was no evidence of implant resorption; there was active formation of new bone around the implant. Implant resorption and osteointegration had started at six months and bone remodeling around the implant was increased. There were signs of bone fusion within and around the cage. Spondylodesis was effective at nine months with bone apposition. Implant resorption continued. Spondylodesis was confirmed. After nine and twelve months implantation, there was no sign of local or general intolerance. Degradation of the implants was visible after one month and appeared to be most marked at 12 months. Approximately 30% of the initial surfaced area of the implants had been resorbed at 12 months.

Conclusion: One year after implantation, the implant had not induced any sign of local intolerance (no sign of inflammation, necrosis, osteolysis). Fusion occurred within and around the case. This study will be pursued (two groups of three animals will be sacrificed at 24 and 36 months) and should confirm the long-term effectiveness of this technique.

Background: Low molecular weight heparins (LMWH) are of undoubted efficacy as thromboprophylaxis in orthopaedic surgical practice. However, prolonged dosage inhibits bone nodule formation in vitro and we have previously reported that daily dosing significantly delays fracture healing. To further investigate these phenomena we hypothesised that LMWH’s would reduce osteoblast survival and thus bone formation by inducing programmed cell death (apoptosis).

Methods: Primary human osteoblasts were isolated from femoral heads excised during hip arthoplasty and cultured to passage 3–5. These were examined for VEGF receptor expression using a biotinylated binding assay on flow cytometry. Osteoblasts were grown to confluence and then incubated for 24 hours in control medium or medium treated with enoxaparin (200 – 2X10(−4) IU/mL) or combination of enoxaparin (200 – 2X10 (−4) IU/mL) and VEGF (1ng/ml). Apoptosis was determined by measuring cytosolic histone-associated DNA fragmentation using an enzyme linked immunosorbant assay. Results were confirmed by DNA fragmentation analysis on agarose gel electrophoresis. Cell functional viability was measured by a tetrazolium bioreduction colorimetric assay.

Results: Data is expressed as percentage of control apoptosis or viability, illustrates mean ± s.e.m. and n=4 experiments in each case. ANOVA was employed for statistical analysis; *versus control, #versus enoxaparin treated; p< 0.05 was considered significant.

Conclusions: Therapeutic doses of LMWH attenuate osteo-blast survival by inducing significant apoptosis. This effect is partly abrogated by VEGF, which independently enhances osteoblast viability, thus delaying spontaneous and enoxaparin induced apoptosis. These findings may explain the bone resorptive effects of prolonged LMWH therapy and suggest a potential therapeutic role for VEGF in conditions of delayed bone formation.

Purpose of the study: The aim of this work was to assess results after treatment by nailing of nonunion of the humeral shaft. In particular, we focused on consolidation and factors predictive of failure.

Material and method: A prospective study was conducted in 13 consecutive patients presenting aseptic nonunion of the humeral diaphysis. There were five cases after orthopedic treatment and eight cases after internal fixation. Two patients had iterative nonunions. Locked nailing was performed with three successive types of nails: the Seidel nail in four cases, the Russel Taylor nail in seven, and the ACE nail in two. Anterograde nailing was used for the first three cases and retrograde nailing for the others. All patients were followed regularly in our department. Last follow-up was one to seven years after nailing.

Results: Five nonunions (38%) did not consolidate after locked nailing. Consolidation was achieved in the other patients after four to 18 months. The anatomic result was good in these patients. Between the success and failure groups, there was no significant difference in age, gender, type of fracture, first intention treatment, delay from fracture to nailing, type or diameter of the nail, surgical access or not to the fracture site during nailing, or duration of complementary fixation. Anterograde nail insertion, used in our first three patients in this series, appeared to affect shoulder function. The retrograde route was used in other patients and did not appear to have any impact on the elbow itself or the elbow region.

Discussion: This clinical study was unable to identify clinical factors explaining failures but did provide several arguments suggesting that defective primary stability of the initial fixation could be incriminated in the failures.

Conclusion: Centromedullary locked nailing is a simple technique with potential for resolving difficult problems of nonunion. Good functional outcome can be obtained when consolidation is achieved. Rather than abandoning this technique, it would be advisable to conduct further research to determine what factors are determinant in its failures.

Purpose of the study: A clinical trial on the treatment of humeral shaft nonunions with locked nailing evidenced 5 failures among 13 cases. The circumstances leading to the nonunion, the patient’s condition, and the nailing method were not found to have a predominant effect explaining this outcome. Inversely, clinical data suggested that abnormal mobility of the nonunion appeared to result from play in the assembly. To check this hypothesis, we measured primary stability in three nailing models using cadaver bones.

Materials and methods: Three nailing models, Seidel (S), Russel-Taylor (RT) and ACE were tested, each on 5 cadaver specimens. A 1 cm segmental resection was made in the mid third of the humerus to simulate an unstable nonunion. The nailing was performed in accordance with the instructions furnished by the manufacturers. The nailed specimens were placed in a testing device which alternatively applied a rotation force around the longitudinal axis (± 0.5 Nm), an axial compression-traction force (± 20 N) and a transverse shear force applied at the level of the osteotomy (± 20 N).

Results: This study demonstrated an instability of the three nails when submitted to a rotation force or a shear force: 14 to 28° and 1.6 to 3.4 mm respectively for the RT nail; 8 to 20° and 1 to 3 mm for the S nail; 5 to 15° and 1.7 to 3.2 mm for the ACE nail. The ACE nail appeared to be more stable when submitted to compression-traction force; the S nail accepted a 0.05 to 0.65 mm play which reached 9.7 mm for the RT nail. This instability appeared to result from play in the locking systems.

Discussion: These findings would demonstrate that these nailing systems cannot, in themselves, provide satisfactory primary stability. The experimentally evidenced instability would contribute, probably in association with locally unfavorable physiological or biological conditions, to the failure rate observed when nailing is used alone.

Conclusion: The locking system for tested nails would have to be modified to eliminate play in the assembly before continuing their use for the treatment nonunion of the humeral shaft.

Severe acetabular fractures are difficult to treat. Complications include blood loss, neural damage, long operating times, and a high risk of sepsis and failure. Even when the fracture is ideally stabilised, there is a major risk of secondary osteoarthritis. This can be related to bone necrosis, cartilage surface damage, bone loss.

However, even in young patients modern surgical techniques, including use of an alumina-against-alumina bearing, may facilitate long-term survival without limitation of activity.

Functionally, the results of secondary procedures after failed osteosynthesis are statistically worse than after primary total hip arthroplasty (THA). The surgery is difficult because of material retrieval difficulties, nerve dissection, bone reconstruction and remaining muscular dysfunction.

We reviewed the results of 80 THA procedures done between 1980 and 1998 to treat 58 acetabular fractures. The mean age of our 57 patients (39 men and 18 women) was 50 years (21 to 80). The mean delay between fracture and THA was 10 years in 22 patients who had undergone osteosynthesis and six years in 35 patients who had been treated conservatively. The mean follow-up period was 5,5 years (6 months to 20 years).

There were eight instances of socket loosening, two of which were septic and six aseptic. Two of these patients had screw-in prostheses and six had cemented. There were 19 sciatic palsies, 13 of which developed after trauma, four after osteosynthesis and two after THA. There were three cases of gluteus medius palsy. In two of four cases of sepsis that occurred after osteosynthesis, sepsis recurred after THA, and in one patient sepsis developed after THA.

In this limited series, patients who underwent THA after osteosynthesis did not have as good an outcome as those in whom initial orthopaedic treatment was followed some weeks later by THA. We believe many poor results could have been avoided with better primary surgery. Functional results are likely to be better, and the incidence of complications lower, if primary THA is performed in conjunction with acetabular reconstruction. Of course, for treatment of simple acetabular fracture involving major displacement of the posterior wall, one column osteosynthesis is still recommended.

High complication rates and technical difficulties of intra-medullary fixation in children with osteogenesis imperfecta has prompted the modification of existing rod systems. The Sheffield telescoping intramedullary rod has T-piece which is permanently fixed and is expanded to reduce metaphyseal migration. This study analyses the outcome of this rod system over an 11-year period.

32 rods were inserted in the lower limbs of 11 children with osteogenesis imperfecta. All children had multiple fractures of the bones before rod insertion.24 rods were inserted into femur, of which 3 were exchange procedures for complications. 8 rods were inserted into tibia. 4 children had intramedullary rodding of all the 4 lower limb bones. The outcome was measured in terms of mobility status, incidence of refractures and rod related complications. Complications encountered include 2-rod migrations, one instance each of broken rod, bent rod and valgus drift in the tibia.There was no instance of epiphyseal damage or growth arrest.

Our series demonstrates that there is significant reduction in refractures and improvement in the mobility status in children with osteogenesis imperfecta following intramedullary fixation. The frequent complication of T-piece separation and the need for reoperation has been overcome with Sheffield modification of rod design. Though the incidence of rod related complications remain high, our study concludes that Sheffield rod system compares favourably with the existing intramedullary devices for osteogenesis imperfecta in the literature.

We have long suspected that patients treated at our institution have narrower femoral canals than the literature suggests. This has implications when it comes to nail size and the question of using reamed or unreamed nails. Using CT analysis, we studied the morphology of the femoral isthmus.

We prospectively evaluated 30 men with a mean age of 26 years (20 to 35). Patients with previous femoral fractures were excluded from the study. A scanogram determined the level of the isthmus and axial cuts at this level accurately revealed canal size and shape.

We found a canal size of less than 12 mm in 62%. In a third of these, canal size was less than 11 mm. Axial cuts showed three types of femoral canals: 14 patients had thick femoral cortices and a narrow canal, seven had thin cortices and a wider canal, and nine had an oval canal, with the larger diameter in the sagittal plane.

If one adheres to the principle of reaming until cortical clutter is heard, the recommended 12-mm or 13-mm reamed femoral nail is not suitable for the majority of non-Caucasian men in our population. Larger nails may cause such complications as delayed union, nonunion and fracture. Smaller nails of 10-mm and 11-mm diameter result in satisfactory clinical and radiological outcomes.

In a retrospective study, we examine the occurrence and management of sepsis in total knee arthroplasty. Histological examination and MCS play important roles.

In the past many high tibial osteotomies were done to relieve symptoms of osteoarthritis. Total knee arthroplasty (TKA) has largely taken the place of these osteotomies.

Aiming to evaluate the long-term results of these osteotomies and assess the complications involved on conversion to TKA, we followed up 207 patients over a 10-year period.

Purpose: The position of the patella after implantation of a total knee arthroplasty is generally determined by static measurements on the femoropatellar 30° flexion view or on a computed tomography (CT) scan in full extension. We studied the kinetics of the patellar implant between 0° and 90° on dynamic CT scans to determine the influence of torsion of the femoral and tibial components on the patellar course.

Material and methods: Twenty patients with titanium total knee arthroplasties implanted in 1991 and 1992 underwent a dynamic CT study preoperatively and during the year following prosthesis implantation. An Imatron machine was used to obtain dynamic slices during knee flexion from 0° to 90°. The patient was installed in the prone position. Slice thickness was 8 mm for images centred on the lower end of the femur. Ten 50 ms images were obtained during flexion from 0° to 90°. The technique used preoperatively and postoperatively enabled study of transversal translation and tilt of the patella.

Results: The orientation of the patellar transversal bony axis remained closely parallel to the flexion axis of the knee (i.e. the epicondylar axis) both preoperatively and postoperatively, irrespective of the orientation of the femoral and tibial components. Between 0° and 90° flexion, the prosthetic patella exhibited a translation movement laterally to medially during the first degrees of flexion then medially to laterally during the last degrees of flexion. The transversal displacement of the patellar insert was less pronounced when the femoral component was placed in external rotation from the epicondylar axis. For femoral implants in internal rotation (mean 5°), the translation of the patellar insert was a mean 1.5 mm between extension and flexion. This translation was only a mean 1 cm for implants in external rotation (mean 5°). Contact between the patellar prosthetic component and the femoral prosthetic component were more harmonious when the femoral implant was placed in external rotation. Torsion of the tibial implant did not appear to have an impact on the transversal course of the patella in this series.

Discussion, conclusion: Rotation of the femoral component influenced the relationship between the patella and the femoral component in flexion-extension movements. However, torsion of the femoral component had little effect on the position of the patella itself. The patellar remained schematically parallel to the epicondylar axis, maintaining an orientation close to that observed preoperatively. The torsion of the femoral implant is the element that modifies its position under the patella and by consequence the relations between the patella and the femoral trochleae. These modifications are more pronounced when the knee is in extension than when the knee is in 90° flexion, excepting for the lift-off phenomenon observed at 90° flexion which is related to the trapezoidal femorotibial resection spaces.

Purpose: Several studies have been conducted to search for factors affecting the prognosis of osteosarcoma. In this work, we attempted to assess the prognostic value of the biopsy technique and initial management on long-term prognosis of localised osteosarcoma of the limbs.

Material and methods: The series included 139 patients (88 males and 51 females, aged 4 to 58 years) with high-grade malignant osteosarcoma of the lower limbs treated or followed by our team between 1984 and 1998. Seventy-eight patients were referred to our unit for biopsy performed by a team surgeon after careful search for local extension and conception of the future extratumour en bloc resection. The 84 other patients were referred to our team after biopsy or after induction chemotherapy. There was no statistical significant difference between the two groups for known prognostic factors (localisation, tumour size, gender). All patients were given pre- and postoperative chemotherapy using the protocols generally applied at the time of their treatment. Three referred patients had already undergone amputation. All others were treated with conservative surgery even in case of fracture, very large tumour or young age. Patients were followed by their surgeon and chemotherapist independently with regular visits every three months for two years then every six months for two years and every year thereafter. Median follow-up was ten years (2.5–16.5 years).

Results: There were 12 local relapses (9%). Two were complications observed among the 75 patients followed from the start in our unit and ten were among the 84 secondary referral patients. Relapse-free survival reached 54% (46/84) in the referral patients compared with 73% (40/55) for the patients initially treated in our unit. For patients treated initially in our unit after 1986, the relapse-free survival rate reached 93%. Multivariate analysis demonstrated that the difference was significant (p < 0.02).

Conclusion: Initial management by an experimented team is a major prognosis factor for long-term survival and for risk of local recurrence in patients with high-grade malignant osteosarcoma of the limbs first seen without metastasis. When the diagnosis of osteosarcoma cannot be ruled out, these patients should be referred to a team specialised in malignant bone tumours before biopsy.

Purpose: The purpose of this work was to evaluate function of 256 total knee arthroplasties (TKA) (Wallaby) with preservation of the posterior cruciate ligament and to compare the femorotibial angle obtained postoperatively.

Material and methods: This prospective study included 256 consecutive TKA (cemented Wallaby 1) in 249 patients (mean age 68 years) with osteoarthritis (n=249) or rheumatoid polyarthritis (n=7). Pre- and postoperative clinical findings (HKS score, flexion, extension, laxity, walking distance, use of crutches) and AP full leg views with 20° loaded lateral views pre- and postoperatively (mechanical femoral, mechanical tibial, and femorotibial angles, tibial slope, patellar height, anterior tibial translation) were recorded.

Results: The 256 TKA were reviewed at a mean 3-year follow-up. Flexion amplitude was the evaluation criterion. Mean preoperative flexion was 109° (40–130°) with mean persistent flexion of 5° (0°–40°). Mean postoperative flexion was 98° (30–130°) with no persistent flexion. The mean preoperative femorotibial angle was 181.8° (160–201°) and was 180.4° (172–195°) postoperatively. The mean preperative mechanical femoral angle was 88° (82–96°) and 89.8° (80–96°) postoperatively. Mean mechanical tibial angle was 93° (85–104°) and 90.4° (84–86°) postoperatively.

Discussion: For certain authors, the only parameter predictive of postoperative flexion after gliding TKA with preservation of the posterior cruciate ligament is preoperative flexion. The statistical analysis of our series showed that correction of the femorotibial malalignement in the frontal plane was not correlated with postoperative knee function and precisely with postoperative flexion. Postoperative flexion was correlated with preoperative flexion. Our results on postoperative flexion of TKA related to preoperative flexion are in agreement with earlier analyses reported in the literature that do not find any absolute correlation with a neutral femorotibial angle in the frontal plane.

Conclusion: The quality of the functional outcome after total knee arthroplasty cannot be predicted solely on the correction of the initial deformity.

Fractures of the thoracolumbar spine are now so common that most orthopaedic surgeons are likely to have to handle one. It is important that we have common terms of reference when we assess, manage and discuss outcomes of these injuries.

The authors plan to assess the intra-observer and inter-observer interpretation of six plain radiographs of thoraco-lumbar fractures. Volunteer orthopaedic surgeons attending the SAOA Congress will be asked to classify the six radiographs twice, on different days, and the radiographic labelling will be changed. Participants will be given the Margel and Dennis classifications for reference. Participants’ names will not be required, only their year of qualification and exposure to spinal surgery.

The results will be analysed statistically and communicated to the orthopaedic community in due course.

Purpose: We report our experience with 10 cases of osteotomy performed at the same time as total hip arthroplasty.

Material and methods: This series included ten knees in ten patients, mean age 63 years. The knees were divided into two groups: five with tibial deviations in one or two planes (three callus deformities, one congenital varus, and one coxalgia sequela) and six mono- or biplanar femoral deviations (three callus deformities, two congenital valgus, and one coxalgia sequela). The principal extra-articular deviation was greater than 10° in all cases. A total knee arthroplasty preserved the posterior cruciate ligament in nine cases with a non-cemented femoral stem implant and cemented tibial implant with or with out a stem. The tibial osteotomies were all in the proximal metaphysis. The femoral osteotomy was in the distal metaphysis in four cases, subtro-chanteric with derotation in one and in the diaphysis with derotation in one. The correction osteotomy was performed before the prosthesis bone cut. Complementary osteosynthesis was used in all cases.

Results: Minimal follow-up was 12 months with a mean of 19.6 months. Bone healing was achieved in all cases. Complete weight bearing was achieved at a mean 2.5 months. The mean postoperative HSS score was 76. Results were excellent in four knees, good in four, fair in one and poor in one. Mean joint amplitude was 105°. Radiographically, complete tibial correction was obtained for three knees (two biplanar corrections); for two knees the biplanar correction was incomplete in one plane. Among the four biplanar femoral deviations, complete correction was achieved in three and incomplete frontal correction in one, with two varus overcorrections in the frontal plane on the single plane deviations.

Discussion: We used this method to avoid intra-articular correction of extra-articular deviations, a source of complications.

Conclusion: Combining osteotomy with total knee arthroplasty during the same operation for patients with major axial deviation and degenerative joint disease provides satisfactory results in 80% of the cases.

Purpose: Bone morphogenetic proteins (BMP) are fragile products that must be protected from degradation and released progressively to achieve maximal efficacy. Release of quantities to the order of 10μg are required at ectopic sites in the rat; in humans 50 mg is required to induce new bone formation. Use of high-dose BMP is costly and the risk of overestimulating mesenchymatous cells remains to be determined. Functional dextranes, or DMCBSU, are inert biological derivatives with random substitution of carboxymethyl, benzylamide and sulfonate units. The affinity of these products for other growth factors led us to propose their use as specific carriers of BMP extracted from bovin bone.

Material and methods: Three different gels (CMDB2, OM27, LS8) and the native dextranes from which they are derived (T40, T500) were tested by to determine their capacity to adsorb and release BMP. Uptake and releasing kinetics were studied by fluorimetry using fluoresceine-labelled BMP. CMDB2 and its native dextrane T500, OM27 and LS8 and their native dextrane TT40, and collagen sponge (control) were implanted in the paravertebral grooves of the rat after impregnating the products with different concentrations of BMP (5 μg, 500 ng, 50 ng, 5 ng). The animals were sacrificed at six weeks. The presence of bone tissue was determined by microradiography and histomorphometry.

Results: The more porous gels (OM27 and LS8) adsorbed the greatest quantities of BMP (96.6 and 95.7 ng/ml respectively). Implantation of BMP associated with certain DMBCSU enabled elaboration of bony tissue in an ectopic site for quantities of BMP starting from 50 ng. This bony tissue formation was obtained for collagen sponge controls with doses 100-fold higher (5 μg). Bony tissue obtained with the BMP:DMCBSU combination was endochondral bone presenting cartilaginous lines, followed by mature bony tissue.

Conclusion: This preliminary study demonstrates that by choosing the right specific carrier for bone growth factors, it is possible to considerably reduce the minimal dose required to induce formation of new bone at an ectopic site. Implantations in bone defects of a critical size are under investigation to validate these results in a model closer to the clinical situation.

Purpose: The purpose of this work was to demonstrate the presence of polyethylene particles at the fixation interfaces of the femoral and acetabular components of non-dislocated cemented hip prostheses that had functioned in vivo for several years.

Material and methods: Three femoral components and two acetabular cups were recovered in two patients who died from an intercurrent cause. The first patient, an 85-year-old woman, had had a hip prosthesis for eight years. There was no radiological sign of displacement nor cup wear (stainless steel /polyethylene cup). For this same patient, the other hip had be revised for acetabular loosening three months prior to death. The femoral component was not loosened; it had been removed with its cement then reimplanted within the same cement sheath that was not removed. The cement/bone interface was thus preserved at eight years. In the second patient, a woman aged 88 years, the delay was nine years. This patient had no radiographic sign of loosening. The polyethylene acetabular insert exhibited 1 mm linear wear. This was a ceramic /polyethylene cup. The specimens were prepared by decalcification and defatting then fixation in buffered formol (pH 7.2) before embedding in polymethyl-metacrylate. After hardening, a diamond-tipped diatome to obtain transverse section of the femur at four levels: lesser trochanter, 2 cm below the lesser trochanter, 1 cm above the tip of the stem, 1 cm below the distal tip of the stem. After polishing, the 50 μ thick sections were stained with Picrofuschin von Jienson. The polyethylene acetabular cups were prepared likewise. Polyethylene particles were counted under polarised optic microscope at each cement /implant and cement /bone interface using an image analyser (Histolab, microvision instruments, Evry, France).

Results: There was no evidence of a fibrous membrane between the bone and the cement. A 10 to 20 mm space was sometimes observed at the metal /cement interface. Polyethylene particles measuring 3 to 10 μm were found at both cement /bone and metal /cement interfaces, including at the distal femur level. Particles were observed in the cement at several sites.

Conclusion: Large-sized polyethylene particles migrate around non-displaced cemented implants, partidularly between bone lines, and can follow the cement poriosity.

Purpose: We analysed outcome of 106 Latarjet-Patte procedures at 7.5 years mean follow-up. Computed tomography of 80 bone blocks provided further details.

Material and methods: One hundred two patients (106 bone blocks), mean age 34 years, were reviewed at a mean 7.5 years follow-up. The sex ratio was 5/1 M/F. The accident had occurred at a mean age of 22 years, by trauma in 87% of the cases, generally involving the dominant limb. Eighty-seven patients practised sports, a high-risk sport in 48% of the cases. Clinical outcome was assessed with the Duplay and Row score, radiographs and a bilateral computed tomography scan in 80 cases.

Results: Postoperative morbidity was 12% and only required revision surgery in 2.8% of the cases. Posterior pain required screw ablation in 6% of the cases. Global outcome was excellent or good in 66% of the patients and 60% of the patients who practised sports were able to resume their activities at the same level. Painless shoulders were achieved for 70% of the patients. There was one post-traumatic recurrence and residual apprehension in 13% of the cases. Grade 3 or 3 osteoarthritis was present in 15% of the cases with a clear narrowing of the joint space in 3.5%. The CT scans were less favourable, showing global or posterior joint space narrowing in 17.5% of the cases. Monocortical screwing led to nonunion in 7%. Advanced osteolysis led to pain with alteration of the functional score.

Discussion: Postoperative complications deteriorated the global result. Overly long malleolar screws led to posterior pain with fatty degeneration of the infraspinatus. Osteoarthritis and “inverted L” subscapularis were the main factors related to loss of rotation. Persistent apprehension was not related to technical error, but to exaggerated anteversion of the humeral cap, basically due to the presence of a notch. Revision scans clearly contributed to the evaluation of the bone block and its position. It allowed a more objective assessment of the osteoarthritis, showing that plain radiographs underestimated both incidence and gravity related to delay after surgery, patient age and the overhanging property of the joint stop.

Conclusion: The Latarjet-Patte procedure has given satisfactory results that can be improved with rigorous technique. Computed tomography provides a more objective analysis of the results.

Although an increased and deeper innervation of painful and degenerate intervertebral discs (IVDs) has been reported, the mechanisms that regulate nerve growth into the IVD are largely unknown. In other tissues, proteoglycans have been found to act as nerve guidance molecules that, generally speaking, inhibit nerve growth. As disc degeneration is characterised by a loss of proteoglycans, we assessed the effects of IVD proteoglycans on nerve growth and guidance.

Using in vitro assays of nerve growth, we found that human disc proteoglycans inhibited nerve attachment, neurite extension and induced sensory growth cone turning in a dose-dependent manner. Digestions with chondroitinase ABC or keratinase abrogated these inhibitory effects. Proteoglycans of the anulus fibrosus were more inhibitory than those from the nucleus pulposus.

Disc proteoglycans inhibit nerve growth and this inhibitory activity may dependent on proteoglycan glycosylation and/or sulfation. A loss of proteoglycans from degenerative discs may therefore predispose the discs to nerve invasion.

One million patients with head injuries present to UK hospitals each year. A significant proportion of these patients have ongoing problems and a large number remain disabled at one year. The management of these patients has recently been criticised by a Royal College of Surgeons Working Party Report (published in June 1999). Several recommendations for the care of head injured patients were made.

We have undertaken a study to examine the way these cases are currently dealt with in Welsh hospitals. A large proportion (75%) of these patients in Wales are cared for by non-neurosurgical consultants with the orthopaedic speciality receiving referrals in most hospitals (55%). A questionnaire was sent to these non-neurological consultants looking after head injuries with specific questions on the current care of these patients and for their opinion on the current system.

We have received an excellent response rate (99%) with the results showing that the Working Party recommendation have not been translated into a change in clinical practice. Our study indicates several shortcomings in the current care of these patients in Wales. It also demonstrates that the almost unanimous (98%) view amongst the consultants that responded is that there is a genuine need for change if we are to offer these patients the best care and rehabilitation in the 21st Century.

A review of scientific literature on whiplash associated disorders was conducted to inform appropriate messages for an evidenced based patient educational booklet, “The Whiplash Book.” The booklet is being developed for use as both a clinical tool and general health intervention.

A systematic literature search was conducted, using MEDLINE and psychINFO, together with hand searches, reference tracking, and the Internet. The Quebec Task Force report and the British Columbia Whiplash Initiative were taken as the starting point. The new evidence covered the period May 1994 through March 2001 (147 articles). All relevant articles were included, with a particular focus on management and treatment of whiplash associated disorders. The quantity, consistency and relevance of all retrieved articles was evaluated, and rated as *** for consistent findings in multiple reports, ** for consensus based on balance of various findings, or * for limited information (single report).

The main messages from the literature suggest: physical serious injury is rare, reassurance about good prognosis is important, over-medication is detrimental, fastest recovery occurs with early return to normal pre-accident activities, self-exercise/manual therapy and positive attitudes/beliefs are helpful to regain activities levels, collars/rest and negative attitudes/beliefs delay recovery and contribute to chronicity.

Introduction: The natural history of bone bruises of the knee and their clinical significance remains unclear with only a few short term studies in the literature.

Aim: This study was designed to try and elucidate the long term outcome of bone bruises of the knee following trauma.

Materials and Methods: 60 patients with bone bruises identified in their knees by MRI scans following trauma were included in the study. All patients were reviewed in a research clinic with a minimum 5 year follow up. A detailed history including mechanism of injury, persistent symptoms and functional status was obtained. Clinical examination to identify intra-articular pathology was then undertaken. All patients had a repeat MRI scan of the knee. The relationship between the injury and the bone bruise, the effect of treatment if any and the long term outcome of such lesions was studied.

Results: 80% of the patients had a twisting injury with our without a hyperextension of valgus/varus force. 58% of our series had ACL injuries and 68% of the bone bruises were in the medial condyle. 72% of the patients did not return to their pre-accident status and had continuing symptoms although the majority of them did not have signs of clinical instability. There was MRI evidence of lasting sequelae of bone bruises in the majority of patients. Detailed results will be discussed.

Conclusions: bone bruises identified on MRI following trauma to the knee are significant lesions with the potential for long term sequelae.

The material most widely used in orthopaedics is hydroxyapatite (HA), anyway many differences are still present between synthetic HA and biological HA. The aim of this study was to compare adhesion, proliferation and differentiation of human osteoblast-like cells on hydroxyapatite discs with different porosity and on plastic cultures.

Human osteoblast-like cells were isolated from 4 young patients (mean age 24.5 years old), treated with collagenase and maintained in Dulbecco’s modified essential medium-10% fetal calf serum. Cells were plated on hydroxyapatite discs with 3 different porosities (35%, 35–55% e 55%) and on plastic cultures used as control. The proliferation was determined by the MTT colorimetric method, and alkaline phosphatase (ALP) activity was measured by a spettrophotometric method. Type I collagen and osteonectin production were demonstrated with fluorescence microscopy and osteoblast adhesion was studied by scanning electron microscopic (SEM) analysis. Results were analysed by one-way analysis of variance (ANOVA).

Osteoblast proliferation on HA was three- to six-fold lower then on plastic. At 28 days, 2141 (± 350) cells/well grew on the most porous disks, with highly significant differences from controls. The ALP production was 2–3 fold lower on HA than on plastic. In the most porous disks, the mean ALP activity was of 2.95 (± 0.07) UI/well after 28 days, higher than in the other two groups. The type-I collagen and the osteonectin fluorescence reaction evidenced a cytoplasmic and a matrix labeling on HA at different porosities. SEM analysis showed osteoblasts with a flattened morphology and only few of them were metabolic active.

At 21 and 28 days, proliferation rate and ALP activity on the three HA cultures were significantly different (p< 0.05). A decrease in cell population and increased ALP activity were observed on the most porous material, and high proliferation and poor differentiation rates on the less porous disks.

Osteoarthritis (OA) is one of the most prevalent diseases of the elderly, affecting greater than 50% of the population over 60 years of age. Many factors are implicated in the development of OA but currently no mechanism has been described that provides an explanation for age as the major risk factor for OA. The present studies were designed to investigate the hypothesis that age-related accumulation of advanced glycation endproducts (AGEs) provides a molecular mechanism that explains (at least in part) the age-related increase in the incidence of OA.

To gain insight in the diversity of AGEs present in articular cartilage, several AGE measures were determined in a wide age-range of normal human articular cartilage samples: all demonstrated increased AGE levels with increasing age. The level of these AGEs was high in cartilage compared to other tissues such as skin, which is mainly caused by the very low turnover of the cartilage matrix proteins. The t1/2 of collagen in articular cartilage is ~117 years (compared to t1/2 of skin collagen of ~15 years).

Accumulation of AGEs in cartilage affected biomechanical, biochemical and cellular characteristics of the tissue. At the biomechanical level, increased AGE levels were accompanied by increased stiffness and brittleness, indicating that AGE accumulation leads to increased susceptibility of articular cartilage to mechanical damage. On the cellular level, accumulation of AGEs decreased the synthesis and degradation (= turnover) of the cartilage matrix. Such decreased cartilage turnover is likely to result in decreased repair capacity of the tissue.

In combination, the AGE-related increase in tissue brittleness and decrease in extracellular matrix turnover, results in articular cartilage that is more prone to damage. This concept, that AGE accumulation predisposes to the development of OA was tested in the canine anterior cruciate ligament transection (ACLT) model for osteoarthritis. Selectively enhancing AGE levels in articular cartilage of young animals (in the absence of other age-related changes) resulted in more severe OA.

Altogether, AGE accumulation in articular cartilage presents a molecular mechanism by which ageing predisposes to the development of OA, and it provides new possibilities for prevention and/or therapy via the inhibition and/or reversal of cartilage AGE formation.

In this outcome-based study, we reviewed the results of the modified Woodward procedure performed on 10 patients over the last 15 years in our unit. The indication for surgery was a unilateral Sprengel’s deformity, Cavendish grade II or III, in children aged 3 to 6 years. Follow-up times ranged from 1 to 15 years. The patients were assessed according to patient and relatives’ satisfaction, cosmesis and functional results.

The modified Woodward procedure entailed a midline longitudinal incision over the spinous processes from C1 to T8. The origins of the trapezius and rhomboids were released from the spinous processes, the scapula lowered and derotated, the superomedial portion of the scapula resected and the trapezius and rhomboids reattached two vertebral levels lower. The clavicle was not osteotomised in any patient. A Velpeau sling was used for four weeks, after which physiotherapy was started.

There were no brachial plexus complications. There were two cases of winging of the scapulae. One patient had a cosmetically ugly scar. Our results showed a cosmetic improvement by an average of one grade and a mean functional improvement of 30° of abduction and flexion. Those patients where an omovertebral body was found and resected had the best cosmetic and functional results. All the patients were satisfied with their operations.

We feel that the pessimism regarding surgical results is unwarranted.

Which of several osteotomies described for approximation of the pubic bones in wide congenital diastasis of the pelvis best facilitates closure is controversial. This paper describes the benefits of the horizontal innominate osteotomy in approximation of the pubic bones when there is wide congenital diastasis.

Between 1994 and 2000, 11 children, ranging in age from one week to eight years, were treated by horizontal innominate osteotomies. Six children had exstrophy of the bladder. There were ischiophagus tetrapus twins and cases of duplication of the genitalia and sacral teratoma. The follow-up time ranged from six months to six years.

General surgical procedures were followed by bilateral innominate osteotomies to facilitate approximation of the pubic bones for bladder, genitalia and anterior abdominal wall repair. The ilium was exposed subperiosteally with the patient supine. A Salter-type osteotomy was performed, dividing the innominate bone from the sciatic notch to just above the anterior inferior iliac spine. The distal fragments were rotated medially, the pubic bones approximated in the midline, and the surgical soft tissue procedures completed. Postoperatively, children were maintained in gallows traction for two weeks and immobilised in plaster for four further weeks.

All osteotomies healed well. Abdominal wound infections occurred in two children, resulting in separation of the pubis. One child had repeat osteotomies one year later and healed well. Abdominal wall hernia occurred in one child. The gap between the pubic bones in the remaining patients ranged from 1cm to- 5 cm. Internal rotation of the hip improved in all patients.

Horizontal iliac osteotomies enable complex pelvic malformations to be corrected without turning the patient. The approximation of the pubis relieves the tension for reconstruction of the bladder, urethra, genitalia and anterior abdominal wall. The procedure is quick and permits single stage closure.

Ceramic-ceramic (C-C) bearings have 20 years clinical experience with alumina ceramics. This system is re-emerging because of its demonstrated excellent wear performance compared to metal-PE or ceramic-PE. However, alumina ceramic imposes a design limitation to reduce breakage risk: most of the implanted C-C systems present a head larger than 28 mm. Zirconia ceramic is three-times more mechanically resistant and has proven its efficiency in ceramic-PE couple. As a result, a new C-C bearing with zirconia head has been studied. Excellent wear performance of the zirconia-alumina (Z-A) combination system has already widely been proven through multilaboratory experiments on a hip simulator. The mechanical aspect is investigated here to analyse the benefit of a zirconia head in a C-C system. This aspect has been first studied by Finite Element Analysis (FEA) and then validated by experimental testing.

The first series of tests on the 28mm system confirmed the FEA predictions: the breakage loads were correctly estimated for each assembly, showing that FEA is an effective tool to predict breakage load and location. The second series of tests were performed on 22.22mm systems. FEA predicted that the Z-A system should pass the 46 kN contrary to the A-A system. Breakage of the A-A system is expected to be in the head.

In conclusion, Z-A combination offers higher mechanical security for the existing C-C designs but above all, larger design choice than A-A system. Considering that wear performances are equivalent, the Z-A system can be thought as the logical evolution of A-A system.

Osteoporosis and osteoporotic fractures represent a growing medical and socioeconomic problem and the spine is the most common site for this kind of fracture. Back pain is the leading symptom with progressive loss of stature and restricted physical activity as a consequence. Vertebroplasty – percutaneous cement reinforcement of osteoporotic vertebrae - represents a new treatment alternative.

During a three year period, 512 vertebrae in 180 patients were reinforced for osteoporotic fractures with low viscosity PMMA. One to eight levels were treated per time, and 8ml (2–18ml) of PMMA per vertebra were injected. The patients’ pain (VAS) was prospectively monitored before surgery, one day, 3 months and one and two years postoperatively. Furthermore, X-rays were analysed 3, 12 and 24 months postoperatively.

One out of 180 patients suffered from an L2 root irritation due to cement leakage that subsided after steroid infiltration. 52 patients with 144 levels treated and a minimal follow up of two years showed a significant (p< 0.02) and lasting pain reduction from 7.7 to 2.8 points at two years. 6 patients were treated a 2nd time for a new fracture. The reinforced vertebrae remained stable without further sintering.

Vertebroplasty is efficient for the treatment of osteoporotic vertebral fractures. The injection technique used is safe, easy and fast. An unsolved problem remains the question about the importance of prophylactic reinforcement of non-fractured vertebrae.

Purpose: We evaluated submuscular anterior transposition of the ulnar nerve at the elbow with lengthening of the medial epicondylars as described by Dellon in patients with ulnar nerf deficiency due to compression.

Material and methods: A consecutive series of 30 submuscular tranpositions of the ulnar nerve in 28 patients were performed between 1994 and 1998. Four patients had had a prior procedure (two simple neurolyses, two subcutaneous transpositions). Mean age was 52 years. Preoperative EMB confirmed the diagnosis of ulnar compression at the elbow. All patients has sensorial and/or motor deficits. Postoperative immobilisation was maintained for 15 to 20 days.

Results: The patients were reviewed at a mean follow-up of four years two months. There were no cases of paraesthesia. Improved sensorial function was observed in 71% of the cases (normalisation in 50%) with improvement in the Foment sign and grip in 81.5% (normalisation in 48%). Mean elbow extension was −5°, and flexion was 135°. There was not limitation on wrist amplitudes. The thumb finger force on the operated side was 78% to 94% that measured on the healthy side and was a function of the MacGowan grade. The palm-finger force was 80% to 95% of the healthy side. There has been no recurrence at last follow-up.

Conclusion: Submuscular transposition using the Dellon technique in 30 cases of ulnar nerve compression at the elbow in patients with ulnar deficiency provided satisfactory sensorial and motor recovery. The usefulness of lengthening the medial epicondyls lies in removing the tension on the ulnar nerve and the little effect on elbow and wrist mobility. Submuscular transposition is the technique of choice for repeated neurolysis.

Purpose: Several techniques have been described for the treatment of unstable fractures of the upper humerus. None appear to be appropriate for subtuberosity fractures, associated or not with a fracture of the trochiter or impacted valgus cephalotuberosity fractures, allowing a stable fixation with anatomic reduction while preserving blood supply to the bone fragments. For the last year, we have studied prospectively a percutaneous minimally invasive technique for this type of fracture. Our preliminary results are analysed here.

Material and methods: We used this technique for 12 patients aged 30 to 87 years with five displaced subtuberosity fractures, six subtuberosity fractures with a trochiter fracture and one impacted valgus cephalotuberosity fracture. Excepting the cephalotuberosity fracture, the joint fragment of the head was reduced by external manipulation under image amplifier guidance. Fixation was achieved with two 25/10 threaded pins inserted percutaneously in retrograde fashio from the anterolateral cortical to the humeral shaft. For eight cases, a third pin was inserted percutaneously from the trochiter to the medial cortical of the humerus. When percutaneous reduction of the trochiter was impossible (three cases) and for the cephalotuberosity fracture, we used a minimal transdeltoid lateral incision to reduce the trochiter and achieve reduction.

Results: Reduction was very satisfactory in all cases. There was one superficial infection that required pin withdrawal at three weeks leading to the only secondary displacement that was minimal and tolerable. We removed the pins after a mean two months. There were no nonunions. Seven patients have a follow-up greater than six months and exhibited a Constant score of 87% (71% to 100%).

Discussion: This techniques has provided very satisfactory results for rapid and stable fixation of the cephalic fragment without loss of blood supply and with a material easy to remove.

Conclusion: These early results are very encouraging and incite us to pursue this technique and analyse long-term results.

Purpose: The rate of failure knee arthrodesis can be high when performed after an infectious complication of a total knee arthroplasty. We evaluated, in 14 patients at a mean 19 months (3–44 months) follow-up, a technique for knee arthrodesis using a custom-made endomedullary implant.

Material and methods: Mean age of these eight women and six men was 68 years. There were 11 patients with an infected prosthesis, one with post-trauma arthritis, one with aseptic loosening of a hinge prosthesis, and one with pseudarthrodesis. For the 12 patients with ongoing infection, surgery was performed in two times with insertion of a spacer (with antibiotics) between the operations. Mean delay between the two operations was 18 weeks. The surgical procedure was associated with a two-drug antibiotic regimen given for a mean three months after arthrodesis. All arthrodeses were stabilised with a custom-made femora-tibial implant with reaming and fixation with two screws. A graft was always used, composed of the reaming products and powder bone substitute in seven cases, reaming products alone in three, and bone-bank heads in four.

Results: Morbitiy: There was one misalignment of the tibial insertion that was not revised. One skin cover problem was treated with a vastus medius flap. One nonunion evolved favourably after a new graft. There were two recurrent infections: chronic fistulae that were controlled by local care and adapted antibiotic therapy. Weight-bearing was started during the first postoperative week in 13 patients. Bone healing (assessed radiographically with resolution of pain) was achieved at a mean three months (2–6 months) in 13 cases. At last follow-up all patients had achieved a satisfactory level of independence.

Discussion: According to the literature, intramedullary devices are superior for consolidating knee arthrodeses, with a lower rate of complications. Use of custom-made endo-medullary implants facilitates the operation and assures better stabilisation of the arthrodesis, allowing rapid weight-bearing. The infection must be controlled before using these implants. The results in our patients are in agreement with the most recent series reported (Barry, Stephen, Kuoan).

Conclusion: In our hands, this type of implant provides an effective means of attaining bony fusion, including in patients who require arthrodesis for an infected prosthesis.

Osteoporotic vertebral fractures are normally attributed to weakening of the vertebral body. However, the compressive strength of the spine also depends on the manner in which the intervertebral disc presses on the vertebral body, and on load-bearing by the neural arch. We present preliminary results from a large-scale investigation into the relative importance of these three influences on vertebral compressive strength.

Lumbar motion segments from elderly cadavers were subjected to 1.5 kN of compressive loading while the distribution of compressive stress was measured along the antero-posterior diameter of the intervertebral disc, using a miniature pressure-transducer. The overall compressive force on the disc, obtained by integrating the stress profile ( 1), was subtracted from the 1.5 kN applied load to give the force resisted by the neural arch. Stress profilometry was performed with each motion segment positioned to simulate the erect standing posture, and a forward stooping posture. Vertebral strength was measured by compressing the motion segments to failure in the forward stooping posture. In life, the spine is usually compressed most severely in this posture.

A univariate analysis of results from the first 9 motion segments (aged 72–92 yrs) showed that vertebral strength increased from 2.0 kN to 4.6 kN as the compressive force resisted by the neural arch in erect postures decreased from 1.1 kN to 0.4 kN (r² = 0.42, p = 0.05). Updated results from this on-going study will be presented at the meeting.

Preliminary results suggest that habitual load-bearing by the neural arch in erect postures can lead to progressive weakening of the vertebral body, which is effectively “stress-shielded” by the neural arch. This weakening is exposed when the spine is loaded severely in a forward stooped posture, when it has a reduced compressive strength. This mechanism could explain some features of osteoporotic vertebral fractures in old people.

Introduction: Occipito-cervical fusion has evolved from the used of simple onlay bone grafts to the use of sophisticated modular implants. Initial stiffness prevents micromotion and allows a higher fusion rate.

Methods: A composite occipito-cervical model (OCM) was developed and validated using data obtained from cadaveric specimens. A jig was designed to pot the OCM, which allowed the application of independent moment forces to simulate flexion, extension, lateral flexion and rotation. The following implants were used 1 ) Grob plate with C1/C2 transarticular screw fixation.2) Grob Plate without C1/C2 transarticular screw fixation.3) Cervifix rod system 4) A Ransford loop system 5.) Olerud plate fixation. A three dimensional ultrasonic motion analysis system (Zebris Inc.) was used to record motion at three positions: 1)C0 2) C2 3) C4.A separate OCM was used for each instrumentation system.

Results: The Grob plate with C1/C2 transarticular fixation was found to confer the greatest initial stiffness. The Ransford loop construct was found to confer the least initial stiffness. Plate fixation offered greater stability then rod or loop constructs. We found the three dimensional motion analysis system to be ideal for displacement analysis in complex spinal instrumentation constructs.

Anatomisches Institut der Georg-August-Universität Göttingen, Germany

Biomedical Research Centre, Dept. of Orthopaedic Surgery, Academic Hospital, Pretoria, South Africa

To date, no animal model for disc degeneration has gained much acceptance, mostly due to the fact that most animals are quadrupeds and thus lack basic biomechanical characteristics of human spines. An adequate model would be of invaluable interest for degeneration related research.

In a standardized series of animal experiments in 18 adult Minipigs and 20 adult Cercopithecus aethiops monkeys all animals obtained nucleotomy in one lumbar FSU from a ret-roperitoneal approach and were sacrificed at last 24 weeks afterwards. The Minipigs were x-rayed at time of sacrifice, the monkeys prior to operation and at termination of the experiment. Vice versa, the Minipigs obtained intradiscal pressure recordings at these occasions. The Minipig spines were formol fixed whereas the monkey spines were harvested after perfusion with PBS, fresh frozen, and obtained CT and MRI scans prior to thawing, fixation and comprehensive histological evaluation.

The lumbar FSU of Minipig and Cercopithecus mainly consists of the same elements as in man. There are certain differences concerning the porcine endplates which ossify as an epiphyseal-like formation with ossification starting in its center, different from the so-called “Randleiste”. Whereas the operative procedure in the Minipigs came in handy, in the Cercopithecus monkey it proved to be demanding, though feasible, due to relatively wide transverse processes and thick psoas muscle structures. The psoas could not be easily detached and needed to be split instead, thus directly exposing the segment nerves. The histological, standard radiological, CT, MRI, and mechanical observations were very similar to those which can be made during the natural aging process of the disc in man.

Both animal models are recommendable for further research: Cercopithecus FSUs are more difficult to expose. Logistic reasons may favour Minipigs in Europe. In case of fusion related experiments the use of primates yet seems inevitable.

Purpose: Bone remodelling and osteolysis around total hip arthroplasty (THA) is a highly debated subject in the medical literature. Such bone behaviour is poorly understood around femoral stems used in revision THA. The main problem is to obtain an objective assessment of bone remodelling and bone reconstruction over time, reconstruction techniques being very variable. Conventional radiology is insufficient, but dual energy x-ray absorptiometry (DEXA) provides a means of following changes in the bone around first intention femoral stems.

Material and methods: We studied bone behaviour around revision femoral stems using the non-cemented “P.P. system”. This type of femoral stem is implanted after trochanter osteotomy to facilitate access and stimulate reconstruction. The series included 31 patients who underwent revision total hip arthroplasty. Follow-up examinations included standard radiographs and DEXA of the operated hips, the contralateral hip and the lumbar spine. Periprosthetic zones defined by Grüen were compared with the same zones in the contra-lateral femur. Mean follow-up was six years.

Results: The standard radiographs did not demonstrate any significant change in periprosthetic cortical thickness. The DEXA demonstrated a significant an average 19.97% reduction in bone density in zones 2, 3, 4, 5 and 6. There was no significant difference in zone 7 and an increase in zone 1 (torchanter osteotomy). These figures are to be compared with the variable thickness observed for first intention pros-theses even shortly after implantation.

Discussion: Our results are the first to our knowledge demonstrating the behaviour of bone around revision femoral stems.

Conclusion: Digastric trochanterotomy appears to be an effective means of stimulating reconstruction of the proximal femur. At equivalent follow-up, the quadrangular section of the revision P.P. stem is more favourable in terms of bone loss compared with first intention stems.

We report on four cases in which the diagnosis of compartment syndrome was delayed by the administration of patient controlled opiate analgesia ( PCA ) following intramedullary nailing of tibial shaft fractures. We believe that this poses a diagnostic problem and can lead to lasting sequelae as decompression is delayed. We present the 4 cases and a review of the literature. We recommend that the use of PCA in patients with intramedullary nailing following tibial shaft fractures be discontinued or used in conjunction with continuous intracompartmental pressure monitoring.

The purpose of this study: is to test the hypothesis that there is little or no stress shielding afforded by a carbon composite femoral hip prosthesis when implanted in the human subject, and to investigate the possibility that a hydroxyapatite coating would prevent loosening.

The need for this development: is that loosening remains a problem for young patients who need a long term, reliable fixation of hip replacements, and it appears that if a solution exists to this problem then it probably lies away from the traditional cemented metal varieties.

One of the causes of loosening is stress shielding caused by rigid metal implants and a carbon composite femoral stem has been developed to overcome this. Paradoxically, flexible stems result in increased micro-motion at the prosthetic-bone interface and as a result they tend to loosen more frequently than metal ones. To overcome this, the carbon stem has been coated on its proximal third with hydroxyapatite, in order to get a secure fixation to the upper femur, but left bare distally to minimise weight transfer within the lower shaft.

The Study: 50 patients have entered the trial to date, and the detailed results of the first 35, which have been followed up for an average of 4 years will be presented. Stress shielding by the prosthesis was assessed, clinically, radiologically, and by dexa-scanning (usinga Hologic scanner with metal exclusion software). Two dexa-scan studies were carried out on each patient, at 1 and 2 years post operatively, and the bone mineral density of the implanted bone was compared with that of the normal contralateral side, using the Gruen zones as the basis of comparison. These results were compared with published figures for metal stems, and also with a small series of our own metal stems.

Results: 13 males and 22 females entered the trial, with an average age of 61.

Bone density around the carbon composite hip was found to increase by an average of 2% between the measurements carried out at 1 and 2 years post-op.

Conclusion: it appears that this prosthesis is fulfilling the predictions made for it, and although there is a spread of responses to it, the average patient is showing a steady increase in periprosthetic bone mineral density and is

Clinically asymptomatic. Progress to a wider trial can now be recommended.

Purpose: Revision of a humeral prosthesis or a total shoulder arthroplasty is a difficult therapeutic challenge. The purpose of this work was to report our experience in a retrospective series of 19 inverted Grammont prostheses implanted during revision procedures.

Material and methods: The series included 11 women and eight men, mean age 66.8 years (45–84). Nine patients had already undergone at least two procedures before the revision of their prosthesis. There were 19 revisions of humeral prostheses and four revision total shoulder arthroplasties. Causes leading to revision of the humeral prostheses were: infection one patient, secondary cuff tears six patients, anterosuperior dislocation of the prosthesis five patients, and stiff and painful shoulders three patients. For the total shoulder arthroplasties, three required revision for a loosened glenoid implant and two for secondary cuff tears with ascension of the humeral head. The same access was used as for the first procedure in most of the cases (deltopectoral or anterolateral approach). The rotator cuff was torn and retracted, or fibrous and non-functional. Ablation of the humeral implant and the cement led to fracture (error or infection) in six cases requiring cerclage for fixation. A complementary bone graft was needed in three cases at the glenoid level in three and at the humeral level in three others.

Results: The Constant score at mean follow-up of 36.4 months (12–60) was 55.07 (44–87) a clear improvement over the initial 13.87 (6–39) before revision. The score was less favourable for patients with several operations before revision. Mean anterior elevation was 29.33° (20–100) pre-operatievely and reached 118.67° (90–160) postoperatively. The pain score was 3/15 preoperatively and13.66/15 postoperatively.

Discussion: Other alternatives may be indicated in salvage situations with an unreparable cuff and a pseudo-paralytic shoulder: rectus or deltoid flaps, reconstruction of the acro-miocoracoid arch and glenohumeral arthrodesis.

Conclusion: The inverted Grammont prosthesis appears to be a useful salvage technique, particularly when the acro-miocoracoid arch is destroyed and the cuff is unreparable. The best chances of success are observed for revision of hemiarthroplasties of a pseudo-paralytic shoulder with complete passive mobility and an anterosuperior dislocation of the humeral prosthesis head.

Glycosaminoglycans (GAGs) govern the osmotic environment of cartilaginous tissues and hence determine their ability to resist the large compressive forces encountered during normal activity. In degeneration GAGs are lost and there is now much interest in biological repair processes where cells from cartilaginous tissues synthesise replacement GAGs and other matrix components in situ. In addition, cells can be grown in tissue engineered constructs. Unfortunately, GAG synthesis is slow.

The aim of this study was to determine whether GAG accumulation could be hastened by increasing cell density in a construct using articular cartilage and intervertebral disc cells cultured in alginate beads.

Bovine chondrocytes and intervertebral disc cells were placed in alginate bead suspension at varying cell densities. GAG synthesis rates, total GAG accumulation and lactate production rates were determined by standard methods. The cell viability profile across intact beads was determined using fluorescent probes.

Increasing cell density causes a reduction in lactate production and sulphate incorporation per million live cells. At greater than 20 million cells per ml, cell death is increased compared with lower densities. GAG produced per bead is not increased in proportion to increasing cell density.

These results show that there is a limit to the rate at which matrix per volume of tissue can be produced and accumulated. At high cell densities cellular activity is limited by toxicity arising from low pH and hypoxia.

One of the mechanisms which controls bone growth, repair remodeling and absorption is mechanical loading. There exists no long-term in vitro model to study bone cells together with their matrix, nor a model that can apply quantitative mechanical forces of physiological amplitudes and frequencies. The analysis of the mechanical properties of bone (Young’s modulus and visco-elastic moduli) on small pieces of bone is also difficult with present devices. We have built a device that can maintain full viability and physiological response of bone for a period of several weeks and integrates all three functions.

10mm diameter bone cores 5 mm thick were obtained from the trabecular bone of the distal ulna of a 24 months old cow by precision cutting with diamond saws and keyhole cutters (our pattern) in sterile 7–10°C phosphate buffered saline (PBS) and cultured in a variation of DMEM containing fructose HI GEM.

Results: The results of these studies have shown that perfusion of trabecular bone can maintain all cells and maintain bone structure for at least 72 days. In conventional methods for bone organ cultures, small bones, such as rat calvaria, quickly start to resorb bone and degenerate. In our perfusion system we see no evidence of change.. Initial experiments have indicated that there are 2 visco-elastic moduli of bone with different time constants, that the elastic modulus of trabecular bone varies is site dependant and that loading to 0.4% compression raises prostaglandin E2 and insulin-like growth factor 1 within a few hours. Mechanical stiffness of bone is increased by 35% when loaded for 20 days at 4,000μ, and decreases by 25% when not loaded. PTH at 10-10M increases stiffness over the load effect and 10-6M PTH decreases stiffness even in the presence of loading. Active osteoclasts are seen during the whole culture period indicating that the stem cells are present and functional.

We gratefully acknowledge support by the German Arthrose Foundation (DAH) and the AO in Davos, CH.

Purpose: Cinematic studies after total knee arthroplasty without an anterior cruciate ligament demonstrate abnormal behaviour compared with the normal knee. The purpose of this cinematic analysis was to examine the knee behaviour after implantation of single-compartment prostheses with an intact anterior cruciate ligament.

Material and methods: The femorotibial contact points were analysed by videofluoroscopy in 20 patients executing a complete weight-bearing extension to flexion movement. These patients had medial (n=16) or lateral (n=4) single-compartment implants. The clinical result in all patients was considered to be very good with a mean HSS score of 97.9 points at a mean 56 months postoperatively. The femorotibial contact points were determined using an automatic computerised adaptation-modelling system. An anterior contact on the medial tibial line in the sagittal plane was positive and a posterior contact was negative. The rotation axis in the craniopodal direction was measured between the anteroposterior longitudinal axis of the femoral component and the fixed axis of the tibial component.

Results: The mean position of the contact point for medial single-compartment prostheses was −90.8 mm in complete extension, −1.4 mm at 30° flexion, −2.4 mm at 60°, and −1.7 mm at 90°. Mean position of the contact point for lateral single-compartment prostheses was −4.0 mm at complete extension, −7.9 mm at 30° flexion, −5.7 mm at 60° and −5/7 mm at 90°. Seven patients with a medial implant and two patients with a lateral implant exhibited paradoxical anterior translation of the femur during flexion. On the average, patients with a medial implant had normal 3.3° axial rotation at 90°; axial rotation was 11.2° for patients with a lateral implant.

Discussion and conclusion: Cinematic analysis of the normal knee has demonstrated anterior femorotibial contact in extension and 14.2 mm posterior rolling of the femoral component during flexion. After total knee arthroplasty without preservation of the anterior cruciate ligament, the rolling movement is limited or absent and a paradoxical anterior translation can be observed. In the present study, the first reported on single-compartment implants, demonstrates that movement is similar to that in the normal knee but with major interindividual variability. A posterior contact at extension and a paradoxical anterior translation can also be observed. This suggests progressive development of anterior cruciate ligament laxity over time, which can at least in part explain the premature polyethylene wear observed after implantation of single-compartment knee implants.

During forward bending activities, the collagenous tissues of the spine are protected from injury by reflex contractions of the back muscles which prevent excessive spinal flexion. Animal experiments have shown that this reflex response is diminished when spinal ligaments are subjected to creep ( 1). This study examined the effects of creep on the latency and amplitude of reflex activation of the back muscles in living people.

Ten healthy volunteers (4M/6F) consented to participate in the study. Subjects underwent two flexion treatments: i) prolonged sitting in a low chair for 2 hours, ii) 100 toe-touching exercises, each on a separate day. Before and after each treatment, subjects performed a standardised forward bending task during which simultaneous measurements were made of lumbar flexion, using the 3-Space Fastrak, and surface EMG activity of the erector spinae muscles at T10 and L3 ( 2). The latency of the reflex response was measured by recording the amount of lumbar flexion that occurred prior to the onset of muscle activation at each site. The amplitude of the reflex was measured by determining the peak EMG activity during the bending task. Each subject’s range of lumbar flexion was also measured independently before and after each treatment to determine the extent of any creep.

Both treatments caused creep, as indicated by a significant increase in the range of lumbar flexion. The treatments also brought about a significant delay in the reflex activation of the back muscles in the standardised bending task: after prolonged sitting, lumbar flexion during the bending task increased by 9.2 ± 7.4° and 5.7 ± 4.6° before the onset of EMG activity at T10 and L3 respectively; following the toe-touches, the equivalent increases in lumbar flexion were 5.4 ± 3.9° and 3.1 ± 4.4°. The amplitude of the reflex response was unchanged following prolonged sitting, but after the toe-touches, a 50% increase in peak EMG activity was observed at L3.

Creep in spinal tissues as a result of prolonged or repetitive flexion was associated with delayed reflex activation of the back muscles. There was no associated reduction in the amplitude of the reflex. The increase in peak EMG activity following the toe touches may reflect increased activation as a result of muscle fatigue. These results suggest that creep in spinal tissues may allow increased lumbar flexion and hence increased bending stresses to be applied to the intervertebral disc.

Purpose: The quality of implantation of single-compartment knee prostheses is a recognised prognostic factor. Acceptable reproducibility can be achieved with traditional instrumentations, although the rate of error can be significant. Computer-assisted implantation might improve results. Most of the currently proposed techniques require supplementary preoperative imaging or implantation of metallic material for guidance. The Orthopilot® system is a purely peroperative system and could thus provide better cost-effectiveness.

Material and methods: We implanted 30 single-compartment knee prostheses using the Orthopilot® computerised system (Aesculap, Chaumont, Group A) and compared the radiographic quality of the implant on telemetric AP and lateral views with those from a control group of 30 single-compartment prostheses implanted with a traditional instrumentation with a femoral centromedullary aiming device (group B). All patients underwent surgery for primary degeneration and were operated on by the same surgeon using the same implant (Search®, Aesculap, Chaumont). The control group was selected among a consecutive series of 250 implants to match the study group for age, gender, importance of the degeneration and frontal femorotibial mechanical angle.

Results: The mechanical femorotibial angle was within desired limits (177±3°) in 26 patients in group A and in 20 patients in group B. Frontal orientation of the femoral component was within desired limits (90±2°) in 27 patients in group A and in 19 in group B (p< 0.05). Frontal orientation of the tibial piece was within desired limits (90±2°) in 27 patients in group A and in 19 patients in group B (p < 0.02). The original level of the joint line was reconstructed with a 2 mm margin in 30 patients in group A and in 24 patients in group B (p < 0.05). Eighteen patients in group A and four patients in group B had optimal implantation for all criteria studied (p < 0.001). There were no system-related complications.

Discussion, conclusion: Computer-assisted implantation is more reliable and more reproducible than traditional instrumentation for the implantation of a single-compartment knee prosthesis. Follow-up results with these prostheses may be better. Systematic preoperative imaging, or preoperative implantation of metallic guide pins is not necessary with this system. The system appears to offer a better cost-effectiveness.