From 1974 to 1989, we treated 50 patients with a simple dislocation of the hip: 38 were posterior dislocations and 12 were anterior. All dislocations primarily treated at our hospital were reduced by closed methods within three hours (mean 85 minutes (10 to 180)) and 43 were reviewed after an average follow-up of 8 years (2 to 17). It is widely held that isolated hip dislocation reduced within six hours gives an excellent outcome, but we found a significant number of complications. There were radiological signs of partial avascular necrosis in two, mild osteoarthritis in seven, and moderate degeneration in two. Heterotopic ossification was seen in four patients, but 29 of 33 MRI examinations were normal. Objective evaluation according to the Thompson and Epstein (1951) criteria showed fair and poor results in 3 of 12 anterior dislocations, but in 16 of 30 posterior dislocations. In six of the seven patients with no other severe injury, the hip had an excellent or good result; in only three of the eight patients with severe multiple injuries was this the case. The important factors in the long-term prognosis appear to be the direction of the dislocation and the overall severity of injuries.

Severe open fractures of the tibia have a high incidence of complications and a poor outcome. The most usual method of stabilisation is by external fixation, but the advent of small diameter locking intramedullary nails has introduced a new option. We report the early results of a randomised, prospective study comparing external fixation with non-reamed locked nails in grade-IIIb open tibial fractures. Of 29 patients, 15 were treated by nails and 14 by external fixation. Both groups had the same initial management, soft-tissue procedures, and early bone grafting. All 29 fractures healed within nine months, but the nailed group had slightly better motion and less final angulation. Complications included one deep infection and two pin-track infections in the external fixator group and one deep infection and one vascular problem in the nailed group. Although the differences in healing and range of motion were not statistically significant, we found that the nailed fractures were consistently easier to manage, especially in terms of soft-tissue procedures and bone grafting. It is the treatment preferred by patients and does not require the same high level of patient compliance as external fixation. The only factors against nailing are the longer operating time and the greater need for fluoroscopy. We consider that locked non-reamed nailing is the treatment of choice for grade-IIIb open tibial fractures.

We report a prospective study of 783 male Israeli recruits aged from 17 to 26 years. The risk of stress fracture was inversely proportional to age on both univariate and multivariate analysis. Each year of increase of age above 17 years reduced the risk of stress fracture by 28%.

We report our experience with a modified implant and a new technique for locked intramedullary nailing of the humerus in 41 patients. Locking was by cross-screws placed from lateral to medial in the proximal humerus, and anteroposteriorly in the distal humerus. Early in the series, 11 nails were inserted at the shoulder, but we found that rehabilitation was faster after retrograde nailing through the olecranon fossa, which was used for the other 30. We used a closed technique for 29 of the nailings. Of the 41 patients treated, 21 had acute fractures, five had nonunion, and 15 had pathological fractures. Secure fixation was obtained for comminuted and osteoporotic fractures in any part of the humeral shaft, which allowed the early use of crutches and walking frames. Two nails were locked at only one end, and one of these became the only failure of union after an acute fracture.

We report seven cases in which open or closed reduction of a shoulder dislocation associated with a fracture of the humeral neck led to displacement of the neck fracture. Avascular necrosis of the humeral head developed in all six patients with anatomical neck fractures. All five anterior dislocations also had a fracture of the greater tuberosity and both posterior dislocations had a fracture of the lesser tuberosity. The neck fracture had not initially been recognised in three of the seven cases. In five cases attempted shoulder reduction led to complete displacement of the head segment, which was treated by open reduction and minimal internal fixation. In the other two cases, shoulder reduction caused only mild to moderate displacement which was accepted and the fracture was treated conservatively. We conclude that biplane radiography is essential before reduction of a shoulder dislocation. Neck fractures must always be ruled out, especially where there are tuberosity fractures. In our series, careful closed reduction under general anaesthesia with optimal relaxation and fluoroscopic control did not prevent iatrogenic displacement. Prophylactic stabilisation of the neck fracture should be considered before reduction of such a fracture-dislocation. It may be, however, that the prevention of displacement by prophylactic stabilisation does not always prevent late avascular necrosis; we observed this in one case.

We report a clinical and radiological survival analysis of 148 consecutive revisions of hip arthroplasties. All patients referred were offered revision if it was indicated and they were medically fit. About one-third (32%) had had at least one previous revision, and about one-third had an established deep infection. The revisions were performed in ultra-clean air with body-exhaust suits. The usual method of fixation was by contained and pressurised cement of standard viscosity, to which appropriate antibiotics had been added in infected cases. Some patients had cementless revision. Clinical failure meant that one or both of the implants had been removed; radiological failure was assessed from serial radiographs. The clinical survival at ten years was 95%. The Merle D'Aubigne and Postel rating for pain improved from a mean of 2.9 to 5.2; and in Charnley group A and B cases, walking ability improved from 2.3 to 4.3. In contrast to some reports we also found good radiological survival; this was 90.5% for cemented femoral stems. Isoelastic revision stems inserted without cement gave poor results.

We reviewed 29 consecutive patients after cemented femoral revision of cemented hip arthroplasties for osteolysis. After an average follow-up of 8.5 years, osteolysis had recurred in only two cases (6.9%) and 25 femoral components (86%) remained well fixed.

We reviewed radiographs and CT scans of 38 total hip arthroplasties which had dislocated (36 posteriorly; 2 anteriorly) and compared the alignment of the prosthetic components with those of 14 uncomplicated arthroplasties. No difference was found between the alignment of the prosthetic components in the two groups. In the seven patients who had reoperations, the cause of dislocation diagnosed by CT was confirmed in only two cases (one retroversion of the cup and one protruding osteophyte). Muscular imbalance rather than malposition of the components was the major factor determining dislocation. CT allows accurate measurement of cup and neck anteversion but contributes little to preoperative planning.

We report the early failure, at a mean of 37 months, of 17 femoral prostheses due to aseptic loosening at the cement-bone interface. In every case the prosthesis had been manufactured with a surface coating designed to enhance the strength of the cement-prosthesis interface. It is postulated that improving the bond at the cement-prosthesis interface may transfer increased stress to the cement-bone interface and cause early failure at that interface.

We report the clinical and tribological performance of 67 ceramic acetabular prostheses implanted between 1976 and 1979 without bone cement. They articulated with ceramic femoral heads mounted on mental femoral stems. After a mean elapsed period of 144 months, 59 sockets were radiographically stable but two showed early signs and six showed late signs of loosening. Four of the loose sockets have been revised. Histological analysis of the retrieved tissue showed a fibrous membrane around all the implants, with fibrocartilage in some. There was no bone ingrowth, and the fibrous membrane was up to 6 mm thick and infiltrated with lymphocytes, plasma cells, and macrophages. Intra- and extracellular birefringent wear particles were seen. Tribological analysis showed total wear rates in two retrieved alumina-on-alumina joints of 2.6 microns per year in a stable implant and 68 microns in a loose implant. Survival analysis showed a revision rate of 12.4% at 136 months.

Interfacial membranes collected at revision from 11 failed uncemented Ti-alloy total hip replacements were examined. Particles in the membranes were characterised by electron microscopy, microchemical spectroscopy and particle size analysis. Most were polyethylene and had a mean size of 0.53 micron +/- 0.3. They were similar to the particles seen in the base resin used in the manufacture of the acetabular implants. Relatively few titanium particles were seen. Fragments of bone, stainless steel and silicate were found in small amounts. Most of the polyethylene particles were too small to be seen by light microscopy. Electron microscopy and spectroscopic techniques are required to provide an accurate description of this debris.

We examined 108 uncemented femoral stems with modular femoral heads which had been retrieved for reasons other than loosening. There were detectable amounts of wear and corrosion in 10 of 29 (34.5%) mixed-alloy components and 7 of 79 (9%) single-alloy components after a mean implantation time of 25 months. We found no correlation between the presence or extent of corrosion or surface damage and any of time in situ, initial diagnosis, reason for removal, age, or weight. Stems with wear and corrosion were less likely to show histological bony ingrowth. The interface between the head and stem of modular total hip components is a possible source of ion release and wear debris, but wear and corrosion were totally absent in most specimens. This suggests that this problem could be avoided, and that further research is required to develop manufacturing methods which would minimise such changes.

Fifty-four cobalt-chrome alloy femoral heads were retrieved at revision surgery or at post-mortem; 23 came from uncemented, eight from hybrid and 23 from cemented hip arthroplasties. The uncemented and hybrid implants had porous coating, metal backing and modular femoral heads; with one exception none of the cemented implants had any of these. Twenty-five of the 31 heads from uncemented and hybrid arthroplasties, and 11 of the 23 heads from cemented arthroplasties showed surface damage involving more than 25% of the surface. Scanning electron microscopy revealed multidirectional fine scratches 1 micron to 10 microns in depth and width which appeared to have been made by fine, hard particles. There was a higher rate of such damage in the uncemented and hybrid arthroplasties than in the cemented implants, suggesting that the abrasive particles were mainly released from the metal, rather than from the cement or polyethylene components of the implants.

The management of radial head fractures complicated by ligamentous disruption remains a matter of controversy. The use of a silicone radial head implant to provide temporary stability is thought to help to protect the ligaments during healing. The reported complications of long-term implantation of a silicone replacement include fracture, dislocation, synovitis, lymphadenitis and subchondral resorption. We now report one case in which an inflammatory process resulted in generalised cartilage degeneration. This has not previously been noted.

We report a review of 54 patients with chronic anterior cruciate ligament rupture treated by patellar-quadriceps tendon graft augmented with polypropylene braid (Kennedy-LAD). The femoral placement of the graft was randomised to either a modified over-the-top (OTT) or a tunnel position obtained by an isometric drill guide (ISO). At the two-year follow-up both procedures had resulted in improvement of subjective knee function and activity level. Stereoradiographic measurements showed reduction of anteroposterior laxity to near normal in about one-third of the patients, but muscle strength and objective functional performance showed little or no changes. The OTT group had better subjective knee function. We were unable to confirm the theoretical advantages of the use of the drill guide, partly because it provided a tibial tunnel which was too anterior.

We report two cases in which arthrodesed knees were revised to total arthroplasties after the use of soft-tissue expanders. Case 1 had had multiple operations on her knee and had been arthrodesed for septic arthritis two years earlier. Case 2 had had knee arthrodesis for severe osteoarthritis 18 years before revision. In both patients, tissue expanders were used to increase the soft tissues available for cover and to help to mobilise the extensor mechanism. The operations were made much easier, and in both patients a range of motion from 0 degrees to 90 degrees was achieved at operation.

We have reviewed 80 children who were involved in the Medical Research Council (UK) trial of surgical treatment for tuberculosis of the spine in Hong Kong. Radical surgery or debridement had been performed at mean ages of 7.6 years (n = 47) and 5.1 years (n = 33) respectively. The patients were followed up to skeletal maturity (mean 17 years). Spinal deformity was measured on lateral radiographs taken preoperatively, at six months, one year, five years and at final follow-up. Radical surgery and grafting produced a reduction in kyphos and deformity angles at six months; this correction was maintained during the growth period. By contrast, after debridement surgery there was an increase in deformity at six months, with a tendency to some spontaneous correction during the growth period. There were statistically significant differences between angles for the radical and debridement groups only at six months postoperatively, but the changes during later follow-up were similar in the radical and debridement groups. Our findings highlight the importance of the surgical correction of deformity, and provide no evidence to suggest that disproportionate posterior spinal growth contributes to progression of deformity after anterior spinal fusion in children.

We investigated the efficacy of a single dose of 1 g of cephazolin in reducing postoperative infections in patients undergoing 'clean' operations on the lumbar spine. In a double-blind, randomised, trial there were 21 wound or urinary infections in the 71 patients who received placebo and nine in the 70 who received cephazolin (p < 0.05). Nine of the placebo patients (12.7%) developed wound infections (complicated by bacteraemia in two) compared with three (4.3%) in the cephazolin group (p = 0.07). Hospital stay was longer for infected patients than for non-infected patients (p < 0.05). Cephazolin-resistant pathogens were isolated more frequently from patients who received cephazolin than from those who received placebo.

The loss of cervical lordosis in radiographs of patients presenting with neck pain is sometimes ascribed to muscle spasm. We performed a cross-sectional study of the prevalence of 'straight' cervical spines in three populations: 83 patients presenting to an accident department with acute neck pain, 83 referred to a radiology department with chronic neck problems, and 80 radiographs from a normal population survey carried out in 1958. Curvature was assessed on lateral radiographs both subjectively and by measurement. The prevalence of 'straight' cervical spines was 19% in the acute cases and 26% in the chronic cases. The 95% confidence interval for the difference was -6.4% to +19.3%. In the normal population 42% showed a straight spine, but a further third of these films had been taken in a position of cervical kyphosis; this probably reflects a difference in positioning technique. Women were more likely than men to have a straight cervical spine, with an odds ratio of 2.81 (95% CI 1.23 to 6.44). Our results fail to support the hypothesis that loss of cervical lordosis reflects muscle spasm caused by pain in the neck.

We assessed narrowing of the spinal canal in 39 burst fractures and fracture-dislocations of thoracolumbar vertebrae treated by the AO Internal Spinal Fixator, using CT preoperatively and at various stages postoperatively. Computer-aided planimetry was used to measure the narrowing, and its restoration shortly after instrumentation, or at 15 months. The mean initial reduction of canal area was to 63.7% +/- 18.8% of normal; this was restored to a mean of 95.4% +/- 21.2% of normal when measured either soon after surgery or at 15 months (p < 0.001 for both groups). There was more improvement in cases assessed later. For fractures from D12 to L3, the mean canal area was restored to 99.4% of normal; but at L4 or L5 the mean restitution was to only 60.9% (p < 0.05). We found no correlation between preoperative loss of area and amount of restoration, or severity of neurological deficit. Nor was there any correlation between the delay before surgery and the improvement achieved. The mechanism of fracture reduction appears to be a combination of distraction ligamentotaxis and forced hyperextension.

We treated 13 children with histologically confirmed cystic tuberculosis of bone. Ten had solitary cystic lesions and three had the multicystic form. Signs and symptoms were related mainly to the joint adjacent to the cyst. Most lesions were in the metaphyses of long bones. They were radiolucent, round or oval, and resembled pyogenic infections, aneurysmal and simple bone cysts, cartilaginous tumours or osteoid osteoma. Only two of the children had pulmonary tuberculosis. The Mantoux skin test was negative in four children and the ESR was normal in five. Curettage followed by anti-tuberculosis therapy for one year resulted in good healing, but two children had residual joint contractures. Biopsy should be taken from the cystic area rather than from the synovium when a joint is involved.

We reviewed 25 children who presented consecutively with voluntary (habitual) subluxation of the shoulder. Thirty-six shoulders were involved and symptoms had been present for an average period of 12 years. Eighteen children were managed by 'skillful neglect': all these had become fully active in the profession of their choice and were satisfied with the outcome. Two of them had required shoulder surgery in adult life but only after trauma. Seven children (ten shoulders) had undergone stabilising operations during childhood with the aim of preventing later degenerative arthritis. These patients were also active in their selected professions, but only three (five of the ten shoulders) had good results: two shoulders had recurrent instability, two were painful and one was stiff. None of the shoulders in either group had developed osteoarthritic changes. There was no association with emotional or psychiatric problems. We conclude that voluntary subluxation of the shoulder in children has a favourable prognosis and that there is no indication for surgical intervention during childhood.

We used hydroxyapatite blocks to keep open Salter innominate osteotomies in 19 children (21 hips), avoiding the need for an autograft taken from the anterior superior iliac spine. Our results were satisfactory, with less deformation of the iliac bone, and a reduction of both blood loss and operating time.

In immature long bones, radical excision of malignant tumours of the metaphysis may necessitate sacrifice of the adjacent epiphysis. To preserve the adjacent joint while allowing a safe margin of excision, we used physeal distraction before removing the tumour. From July 1984 to August 1992, we operated on 20 patients by this method. After a mean follow-up of 54 months there was no local recurrence in the epiphyseal region. Three patients had developed pulmonary metastases.

We examined 16 feet, 33 to 133 months (mean 83) after simultaneous calcaneocuboid and talonavicular fusions performed for a variety of painful disorders of the hindfoot. Objectively, four feet were rated excellent, eight good, four fair and none poor. There was one asymptomatic nonunion of the talonavicular joint. Progressive degenerative arthritis of the ankle was seen in six patients and of the naviculocuneiform joint in seven. Biomechanically, simultaneous calcaneocuboid and talonavicular arthrodesis is better than an isolated talonavicular fusion and is a simple and effective alternative to triple arthrodesis.

Mucormycosis is an opportunistic infection that very occasionally causes osteomyelitis and avascular necrosis of bone. The infection may prove fatal if not diagnosed promptly. If early treatment is instituted the prognosis is good.

A study of heel-pad thickness and compressibility using lateral radiographs, loaded and unloaded by body-weight, was carried out on 70 patients with plantar heel pain and 200 normal subjects. The heel-pad thickness and the compressibility index (resistance to compression) were greater in the patients than in normal subjects and significantly increased with age. In normal subjects, the thickness was greater in males than in females, but there was no significant difference in the compressibility. Increased weight led to an increase in heel-pad thickness and compressibility index. The body mass index was greater in patients with plantar heel pain than in normal subjects and 40% of the patients were considered to be overweight. Increase in the compressibility index indicates loss of elasticity and an increased tendency to develop plantar heel pain.

We performed isokinetic knee testing to assess thigh muscle function in ten patients (12 legs) before and after mid-shaft femoral shortening averaging 46 mm (27 to 70). Tests were at angular velocities of 60 degrees/sec and 180 degrees/sec, and were performed preoperatively and after 3, 6, 12 and 24 months. Isokinetic tests at two years showed a significant reduction in muscle function in both quadriceps and hamstrings, but recovery of function was significantly better for the hamstrings. There was a linear relationship with correlation of r2 = 0.31 to 0.86 between loss of muscle force at two years and the magnitude of shortening. Long-term loss of muscle force should be expected after a mid-shaft shortening of the femur of more than 10%.

The palmar ligaments of the wrist were dissected in 15 adult cadaver wrists and demonstrated by MRI in three. Ten fetal wrists (10 to 19 weeks' gestation) were studied in histological sections. The palmar scaphotriquetral ligament was found in them all. Its attachment to the triquetrum is substantial but that to the scaphoid is thin and fan-shaped, its fibres interdigitating with those of the radioscaphocapitate ligament. The contribution of the ligament to carpal stability has yet to be studied, but it may help to support the head of the capitate when the wrist is dorsiflexed.

A computer-assisted method of preoperative planning was used to create virtual models of the deformed distal end of the radius after malunion of a fracture. By comparison with a similar model of the uninjured wrist, values were calculated for the angles and lengths to be corrected by osteotomy. Shifts of the distal fragment were analysed for 33 deformed wrists, 27 of which underwent corrective osteotomy and bone grafting. In more than half the cases there was dorsal or volar shift of 3 mm or more. The accuracy of the correction was measured by comparing the three-dimensional models before and after osteotomy with the model of the normal wrist. The volar and ulnar inclination angles of the articular surface of the radius and the radial length were regularly restored to normal.