In recent years, machine learning (ML) and artificial neural networks (ANNs), a particular subset of ML, have been adopted by various areas of healthcare. A number of diagnostic and prognostic algorithms have been designed and implemented across a range of orthopaedic sub-specialties to date, with many positive results. However, the methodology of many of these studies is flawed, and few compare the use of ML with the current approach in clinical practice. Spinal surgery has advanced rapidly over the past three decades, particularly in the areas of implant technology, advanced surgical techniques, biologics, and enhanced recovery protocols. It is therefore regarded an innovative field. Inevitably, spinal surgeons will wish to incorporate ML into their practice should models prove effective in diagnostic or prognostic terms. The purpose of this article is to review published studies that describe the application of neural networks to spinal surgery and which actively compare ANN models to contemporary clinical standards allowing evaluation of their efficacy, accuracy, and relatability. It also explores some of the limitations of the technology, which act to constrain the widespread adoption of neural networks for diagnostic and prognostic use in spinal care. Finally, it describes the necessary considerations should institutions wish to incorporate ANNs into their practices. In doing so, the aim of this review is to provide a practical approach for spinal surgeons to understand the relevant aspects of neural networks.

Cite this article: Bone Joint J 2021;103-B(9):1442–1448.

Abstract

Balloon kyphoplasty (BKP) is a minimally invasive surgical technique used to correct kyphosis and vertebral compression fractures. BKP uses cement to fill a void created by the inflation of a balloon in a vertebra, it can be used as an alternative to vertebroplasty to reduce cement extravasation. Issues such as poor inter digitisation of the cement and the trabecular bone can arise with the BKP method. This can be due to a compacted layer created during the procedure which can cause complications post-surgery. The primary aim of this study was to investigate alternative cement application methods which could improve the mechanical strength of the bone-cement interface. Three alternative methods were investigated, and cylindrical bone-cement specimens were created for all methods (BKP and three alternatives). An important part of this study was to replicate the compacted layer created by the inflation of the balloon tamp in BKP. Synthetic trabecular bone specimens (Sawbones®, Pacific Research Laboratories, Vashon Island, Washington, USA) were pre-loaded in compression and the resultant compacted layers were found to replicate the compacted layers found in surgery. Mechanical testing was carried out with an MTS Model 858 Bionix^® Servohydraulic load frame using static tensile and torsion loads. Static tests revealed that two of the three alternative methods were an improvement on BKP, with a high statistical significance in relation to the mechanical performance of the bone-cement interface (P < 0.001). This data illustrates the potential to improve the standard BKP technique, in terms of bone-cement interface performance.

Aim:

To compare the degree of deformity correction achieved using cobalt chromium versus titanium alloy rods in patients with Adolescent Idiopathic Scoliosis.

Aim:

Deep infection following paediatric spinal deformity surgery is a serious complication, which can also result in increased length of stay and significant cost implications. Our objective was to reduce deep infection rates following spinal deformity surgery.

Aim:

To determine if patients with coronal plane deformity in the lumbar spine have a higher grade of lumbar spine subtype compared to controls.

Aim:

Recent guidelines have been published by the Association of Neurophysiological Scientists / British Society for Clinical Neurophysiology (ANS/BSCN) regarding the use of intra-operative neurophysiological monitoring (IOM) during spinal deformity procedures. We present our unit's experience with IOM and the compliance with national guidelines.

In a time of limited resources, the debate continues over which types of hip prosthesis are clinically superior and more cost-effective. Orthopaedic surgeons increasingly need robust economic evidence to understand the full value of the operation, and to aid decision making on the ‘package’ of procedures that are available and to justify their practice beyond traditional clinical preference.

In this paper we explore the current economic debate about the merits of cemented and cementless total hip replacement, an issue that continues to divide the orthopaedic community.

Cite this article: Bone Joint J 2013;95-B:874–6.

Introduction

This study sought to determine whether the functional outcome of two common spinal operations could be improved by a programme of post-operative rehabilitation and/or an educational booklet each compared with usual care.

Introduction

Lag screw cut-out following fixation of unstable intertrochanteric fractures in osteoporotic bone remains an unsolved challenge. A novel new device is the X-Bolt which is an expanding type bolt that may offer superior fixation in osteoporotic bone compared to the standard DHS screw type device.

Aim

Evaluate the outcome and complications of anterior pubic symphysis plating in the stabilisation of traumatic anterior pelvic ring injuries.

Introduction

Mortality rates following hip fracture are high. There are several scoring systems which aim to predict morbidity and mortality in hospital in-patients. The Nottingham Hip Fracture Score (NHFS) was devised to predict 30 day mortality following hip fracture.

Background

Malnutrition has been suggested to increase the risk of falls in frail elderly. It has been hypothesised that elderly, orthopaedic trauma patients may be malnourished. We conducted an observational study to identify if this was the case.

Introduction

Acetabular fractures are a challenging problem. It has been published that outcome is dependent upon the type of fracture, the reduction of the fracture and concomitant injuries. The end-points of poor outcome include avascular necrosis of the femoral head, osteoarthritis. However, we lack definitive statistics and so counselling patients on prognosis could be improved. In order to achieve this, more outcome studies from tertiary referral centres are required. We present the first long term follow up from a large tertiary referral centre in Ireland.

Introduction

Acetabular fractures are a challenging problem. It has been published that outcome is dependent upon the type of fracture, the reduction of the fracture and concomitant injuries. The end-points of poor outcome include avascular necrosis of the femoral head, osteoarthritis. However, we lack definitive statistics and so counselling patients on prognosis could be improved. In order to achieve this, more outcome studies from tertiary referral centres are required. We present the first long term follow up from a large tertiary referral Centre in Ireland.

Introduction

Mortality rates following hip fracture are high. There are several scoring systems which aim to predict morbidity and mortality in hospital in-patients. The Nottingham Hip Fracture Score (NHFS) was devised to predict 30 day mortality following hip fracture. Methods: All patients with hip fractures admitted over a 6 month period were reviewed. The NHFS was calculated for each patient and any associations between patient factors, NHFS, and outcome were investigated.

There is controversy regarding the optimum method of stabilising traumatic anterior pelvic ring injuries. This study aimed to evaluate the role of pubic symphysis plating.

Controversy exists whether a single proximal lateral tibia (PLT) locked plate is adequate for bicondylar fractures and whether the use of integral raft screws makes the use of bone graft less important.

57 consecutive patients who underwent reconstruction with a locked PLT plate were retrospectively reviewed. Radiographs were examined for operative reduction and subsequent loss of reduction.

55 patients were followed-up for an average of 27 weeks. Fractures were divided into unicondylar (Group 1, n=33) and bicondylar (Group 2, n=22). Union occurred in all patients, with no revisions or removal of metalwork at final follow-up. In 50 patients (88%), the fracture was reduced to within 2mm of anatomical. Articular surface collapse of >2mm occurred in three patients. Nine patients underwent bone grafting with no difference in outcome. A supplementary medial plate was used in three patients with a separate posteromedial fragment.

Except for a separate posteromedial fragment, the use of a single locked PLT plate for bicondylar fractures allows union to occur without failure. With the use of integral raft screws, the need for bone graft is questionable. The short-term radiological results and complication rate of PLT locked plating is excellent.

Background

There is minimal published data regarding the long-term functional outcome in pyogenic spinal infection. Previous studies have used heterogeneous, unreliable and non-validated measure instruments, or neurological outcome alone, yielding data that is difficult to interpret. We aim to assess long-term adverse outcome using standardised measures, Oswestry disability index (ODI) and MOS short form-36 (SF-36).

Objective: The deltoid ligament is an important stabilising structure in the ankle joint. We hypothesised that ultrasound can be used to allow early clinical assessment of ankle fracture stability accurately and quickly in Weber B and C ankle fractures thereby negating the need to perform arthrograms intra-operatively.

Method: A total of 20 patients were recruited prospectively. Consent was obtained prior to surgery. Patients with Weber B or C fractures requiring surgery were recruited prospectively. Following induction of anaesthesia, ultrasound examination was performed, followed by an arthrogram under fluoroscopic screening. Operating surgeons were blinded to results. Radiographs, ultrasound and arthrographic findings were compared by a panel of orthopaedic surgeons of varying grades (2 Consultants, 2 Specialist Registrars).

Results: There was 95% correlation between ultrasound and arthrogram findings. Ultrasound accurately diagnosed rupture with a sensitivity of 92% and specificity of 100%. Kappa scores for ultrasound identification of deltoid rupture was 0.8.

Conclusion: We feel ultrasound exam to be a powerful adjunct tool in the management and operative planning of ankle fractures. Its versatility means it can be used in Emergency Departments and Trauma Clinics to assess ankle stability without causing the patient excessive pain and requiring an anaesthetic.

Use of epidural analgesia post-operatively in spinal surgery is becoming increasingly common. We have conducted a prospective study examining the side-effects associated with epidurals and the need for additional analgesia in 36 adult patients undergoing either lumbar spine decompression, lumbar spine fusion, or a combination of decompression and fusion. A mixture of bupivacaine and fentanyl was used for up to 72 hours post-operatively via an epidural catheter placed under direct vision at the time of surgery. All patients had urinary catheters inserted peri-operatively.

15 patients experienced one or more side-effects; 6 patients had a subjectively unpleasant sensory block, 3 patients developed a motor block, 4 patients had pruritus, 3 developed hypotension, and 2 had episodes of nausea or vomiting. All these features resolved upon reduction of the epidural rate or cessation of the epidural. All patients required additional oral analgesia at some point during their observation. There were no serious complications, such as infection, permanent neurological deficit, or cord compression.

We conclude epidural analgesia following lumbar spine surgery is a safe practice, although the high rate of side-effects necessitates close observation by fully trained staff. It appears additional oral analgesia is required to obtain satisfactory levels of analgesia.

It has been suggested that recent reduction in hours worked by orthopaedic trainees in the UK may result in less exposure to operative procedures.

To examine this possible change, operative data showing the participation of specialist registrars in orthopaedic trauma cases were examined over 6-month periods in 2002 and 2007. Operations specifically examined included dynamic hip screw, hip hemiarthroplasty, manipulation under anaesthetic, ankle fracture fixation, and tension band wiring. A traditional on-call system was used throughout but the number of working hours was reduced.

Analysing individual operations, the results demonstrated a general trend for trainees to perform fewer procedures in the 2007 group, but this difference was not statistically significant. Level of consultant supervision was not significantly different except for hip hemiarthroplasty, which was higher in 2007. When considering all operations together, there was a significant decrease in the number of procedures performed by trainees in 2007, and although there was a trend for more supervision, this was not significant. Trainees were present for a significantly lower proportion of procedures in 2007 than 2002.

We conclude that it appears operative experience in orthopaedic trainees may be less than 5 years ago and this may be associated decreased attendance in theatre.

Immobilisation is known to be a risk factor for thromboembolic events and the management of ankle fractures often involves immobilisation of the fracture in a below knee cast. Recent literature has found a 5% rate of subclinical deep vein thrombosis (DVT) and suggested thromboembolic prophylaxis is not required.

This study involved all adult patients with isolated ankle fractures presenting to a district general hospital orthopaedic department over a 6 month period. This included patients undergoing internal fixation as well as non-operative management. A 3 to 7 month follow-up was performed to assess the incidence of clinical DVT or pulmonary embolism (PE) proven using Doppler imaging, venogram, and computed tomography pulmonary angiography. 119 patients met the entry criteria and, of these, 3 patients developed DVT and 2 patients presented with pulmonary embolus. 15 patients in the study were taking aspirin (75–300 mg daily) during their cast immobilisation and 1 patient was taking warfarin. None of these patients developed a thromboembolic complication. 4.8% of patients not taking aspirin or warfarin experienced a thromboembolic complication.

This study demonstrates a relatively high incidence of symptomatic thromboembolism following ankle fractures in the absence of prophylaxis. Previous studies have found aspirin to be an effective method of prophylaxis following hip fractures and total hip arthroplasty. We recommend that thromboembolism prophylaxis is necessary following ankle fractures and suggest that aspirin may be an economical option. Larger studies are needed to evaluate the role of aspirin in this setting.

Introduction: Weber B fractures are one of the most common fractures of the ankle. Unstable fractures are treated with lateral plating and a lag screw. Another method of fixation is antiglide plating, this concept was first introduced by Brunner and Weber in 1982.

Manoli and Schaeffer in 1987, showed that fixation by antiglide plate demonstrated superior static biomechanical properties compared to lateral plating.

However there are some shortcomings in their study and hence we decided to perform our biomechanical study. The shortcomings of the Manoli study are. They did not use an interfragmentary lag screw for lateral plate fixation. It was a cadaveric study where the bone does not accurately represent the live bone. The quality of the bone ranging from normal to osteoporotic bone varies from cadaver to cadaver and hence there is no uniformity between the samples.

Materials and Methods: We used 4th generation composite bone models validated to closely simulate human bone characteristics for fracture toughness, tensile strength, compressive strength, fatigue crack resistance and implant subsidence. 4th generation composite bone model provides uniformity of test samples which is not achievable in cadaveric studies.

These bones were custom made for the experiment. We used two sets of bones, one representative of normal bone (Set A n=10) and the other of osteoporotic bone quality (Set B n=10). Each of the sets A & B will have two types of fixations for artificially created Weber B Fractures.

Lateral plate with interfragmentary lag screw.

The strength of the fixation was measured by restressing the bone until the fixation failed using an Instron machine which simultaneously applied torque and compressive forces to the fibular construct. The resulting data was analysed on a computer and statistical analysis was performed.

Results: When the two fixation constructs were stressed to failure, the lateral plate construct demonstrated less stiffness (3–5Nm/degree) and failed at lower energy levels (250Nm). Similar values obtained for the antiglide system were, stiffness of 12–16Nm/degree and energy absorbed to failure 350–450Nm. Antiglide plating was significantly more stable in the osteoporotic fibula.

Conclusion: Antiglide plating with lag screw is much more stable than lateral plating. It is suitable for treatment without plaster cast post operatively. It results in a more stable fixation in osteoporotic bone.

Coronal alignment is an important factor in long-term survival of TKA. Many implant systems are available and most aim to produce a posterior slope on the tibial component to reproduce the 7⁰ seen in the normal tibia. We hypothesized that resecting the tibial plateau with a posterior slope can introduce error in coronal plane alignment in TKA.

We used a standard saw-bones model in conjunction with a computer navigation system that is available for use in TKA (Stryker Orthopaedics). The normal protocol for preliminary referencing was followed; care was taken to identify tibial landmarks (tibial plateau reference point, true sagittal plane and transmalleolar axis). We then used a standard extramedullary alignment jig (Scorpio TKR System, Stryker Orthopaedics) with cutting blocks designed to give 0, 3, 5 and 7 degrees of posterior slope and varied the position of the alignment jig.

Variations included:

Medial rotation of the cutting block,

In all experiments, there was a greater deviation from ideal coronal alignment as the slope on the tibial cut was increased. The greatest influence was with external rotation of the distal part of the jig, which produced 3⁰ of varus at only 15⁰ of external rotation with a 7⁰ slope. Medialisation of the proximal reference point worsened this to 4.5⁰ of varus.

We have quantified the degree of coronal malalignment that can occur for different posterior slopes during tibial resection for TKA. We recommend either using a minimal slope or navigation to ensure correct implant positioning.

Correspondence should be addressed to Major M Butler RAMC, Princess Elizabeth Orthopaedic Centre, Royal Devon and Exeter Hospital, Exeter, Devon.

There is little published data concerning long-term outcome in pyogenic spinal infection. Previous studies have used either neurological outcome in isolation, or non-validated quality of life measure instruments yielding data that is difficult to interpret.

To assess long-term outcome following pyogenic spinal infection through standardised outcome measures, Oswestry Disability Index (ODI) and Short Form-36 (SF-36) were utilised.

All cases of pyogenic spinal infection presenting to a single institution over the period 1993–2003 were retrospectively identified. Inclusion in each case was based on consistent clinical, imaging and microbiology criteria. The follow-up was by clinical review, American Spinal Injury Association (ASIA) classification, ODI and SF-36. The outcome was compared to normative data for the Irish population.

Twenty-nine cases of pyogenic spinal infection were identified. Nineteen patients (66%) had an adverse outcome at a median follow-up of 61 months, despite only 5 patients (17%) who had persistent neurological deficit according to ASIA classification. A significant difference in SF-36 PF (physical function) scores was observed between patients with adverse outcome and those who recovered (p=0.003). SF-36 scores failed to reach those of a normative population, even after apparent full recovery. A strong correlation was observed between ODI and SF-36 Physical Function scores (rho=0.61, p< 0.05). Seventeen percent (n= 5) of admissions resulted in acute sepsis-related death. Delay in diagnosis of spinal infection (p= 0.025) and neurological impairment at diagnosis (p< 0.001) were associated with neurological deficit at follow-up examination. Previous spinal surgery was a significant predictor of adverse outcome in patients requiring readmission < 1 year (p= 0.018).

The finding of high rates of adverse outcome and using SF-36 and ODI suggests under-reporting of poor outcome in other series. We advocate use of validated standardised spinal outcome questionnaires to accurately assess long-term outcome and facilitate comparison between case series.

Background: Coronal alignment is important in long-term survival of TKA. Many systems are available; most aim to produce a posterior slope on the tibial component in order to reproduce the 7⁰ seen in the normal tibia. Some are designed to produce a bone cut with 7⁰ of slope whereas others combine the slope of the bone cut with an in-built slope on the polyethylene insert. We have investigated the theory that resecting the tibial plateau with a posterior slope can introduce error in coronal plane alignment in TKA.

Methods: We used a standard saw-bones model in conjunction with a computer navigation system that is available for use in TKA (Stryker Orthopaedics). The normal protocol for preliminary referencing was followed; care was taken to identify tibial landmarks (tibial plateau reference point, true sagittal plane and transmalleolar axis). We then used a standard extra-medullary alignment jig (Scorpio TKR System, Stryker Orthopaedics) with cutting blocks designed to give 0, 3, 5 and 7 degrees of posterior slope and varied the position of the alignment jig. Variations included:

Medial rotation of the cutting block

Results: In all experiments, there was a greater deviation from ideal coronal alignment as the slope on the tibial cut was increased. The greatest influence was from external rotation of the distal part of the jig which produced 3⁰ of varus at only 15⁰ of external rotation with a 7⁰ slope. Medialisation of the proximal reference point worsened this to 4.5⁰ of varus.

Conclusions: We have quantified the degree of coronal malalignment that can occur for different posterior slopes during tibial resection for TKA. We recommend either using a minimal slope or navigation to ensure correct implant positioning.

The use of arthroplasty registers was initiated by Sweden in 1979. The practice has been adopted globally as best practice for recording the outcome of joint replacement surgery and for identifying early problems. The Trent and Wales Arthroplasty Audit Group began in 1990 and have recently produced outcome results. We have analysed the short-term outcomes of arthroplasty procedures at a DGH in order to assess comparability to this “gold-standard”.

In 2004, 231 primary arthroplasties were performed, by the two senior authors, at Musgrove Park Hospital (149 THR, 82 TKR). There was an overall complication rate of 8.7%. There was 1 periprosthetic infection in a THR that required revision (0.043%). 9 patients developed wound complications, principally superficial infections and haematoma formation. 2 patients, both THR developed, thromboembolic complications, one DVT and one pulmonary embolus. There was one periprosthetic fracture around a THR. The dislocation rate for THR was 3.35% (5/149). 3 of these were performed through a posterior approach and 2 through an anterolateral. 3 have required revision surgery.

We have demonstrated comparable results following joint arthroplasty to published teaching hospital series. We have shown that adequate infrastructure can exist in smaller units to accurately record outcome data following arthroplasty surgery.

Shoulder Arthroscopy techniques may pose surgical risk to vascular structures that may cause active bleeding during surgery. The vascularity of the subacromial structures showed constant patterns of distribution and specific sources of bleeding were analyzed. Knowledge of the vascular anatomy may decrease the bleeding during subacromial arthroscopy surgery.

Shoulder Arthroscopy techniques may pose surgical risk to vascular structures that may cause active bleeding during surgery. A detailed anatomy map of frequent sources of bleeding is more than desired in order to properly identify these bleeding points, and avoid the unnecessary overuse of thermal tools and pressure pumps to control the hemorrhage.

Our purpose is to study the vascular anatomy of the subacromial space, and to map the major sources of expected bleeding during subacromial arthroscopy surgery.

Ten shoulders of five adult cadavers underwent whole body arterial perfusion with a mixture of lead oxide, gelatin and water. The shoulders were dissected, photographed, tissue specimens were radio graphed, scanned and analyzed with a digital software analyzer. Careful dissection of the different arteries of the subacromial bursa, and anatomic landmarks of the walls were documented. Correlations of bleeding areas during subacromial arthroscopic surgery and cadaver dissection were carried out. A vascular map of the bursa was created.

The vascularity of the subacromial structures showed constant patterns of distribution and specific sources of bleeding were analyzed. We divided this space into walls with their major arteries as follows: Anterior wall: Acromial branch of the thoracoacromial artery. Posterior wall: Acromial branch of the suprascapular artery. Medial wall: Anterior and posterior Arteries of the AC joint. Lateral wall: No major arteries identified. Vascularity of the roof and floor is also described.

The subacromial space is highly vascular. Knowledge of the vascular anatomy may decrease the bleeding during subacromial arthroscopy surgery.

Introduction: The incidence of osteoporosis is increasing as the population ages. Amongst the recommended treatment modalities for osteoporosis is the use of bisphosphonates. The National Osteoporosis Foundation (U.S.A.) recommends DEXA scanning prior to commencing treatment with bisphosphonate therapy. However, in the Irish setting the availability of DEXA scanning is often limited. We hypothesised that a high percentage of elderly women presenting with fragility fractures of the distal radius (following a simple fall from standing height) had underlying osteoporosis. As such, the initiation of treatment with bisphosphonates prior to obtaining a DEXA scan may be warranted in this patient cohort.

Aim: To assess the incidence of osteoporosis in a continuous cohort of women over 60 years of age presenting with fractures of the distal radius.

Patients and Methods: All female patients aged > 60 years old presenting to the fracture service over a five month period with distal radial fragility fractures were evaluated. Exclusion criteria included:

non-English speakers

100 consecutive patients presenting to the fracture service with distal radial fragility fractures were prospectively identified. Data was collected, including body mass index (BMI), risk factors for osteoporosis, and the OST risk index calculated. A DEXA scan was then performed on the patient’s hips and lumbar spine.

Results: The mean patient age was 74.3 (95%CI + 10.6) years. Mean BMI was 17.3 kg/m2. The mean Osteoporosis Self-assessment Tool (OST) index score was 0.65 correlating with a moderate risk for osteoporosis. The mean T score for the patients’ hips was −2.0 while that for the lumbar spine was −1.7. 64% of patients were osteoporotic with a T score of less than −2.5.

Conclusions A significant incidence of osteoporosis was noted in the study cohort. It is imperative that orthopaedic surgeons recognise the high incidence of osteoporosis in the elderly female population presenting with fragility fractures. The high morbidity and mortality associated with hip and vertebral fractures in this population may be prevented by early treatment of underlying osteoporosis.

Introduction: The increasing popularity of minimal access surgery in orthopaedic surgery has resulted in increasing use of intra-operative fluoroscopy. The radiation dose received by the surgeon varies from procedure to procedure depending on several factors such as duration of procedure, direct exposure to radiation beam and distance from the radiation source. In particular hand and wrist injuries often involve direct fluoroscopic exposure to the hands of the surgeon and assistant during the procedure.

Aim: We undertook a prospective study to directly evaluate the exposure of the surgeon’s and assistant’s hands and thyroid glands during K-wiring procedures of the hand and wrist. In addition we evaluated the efficacy of a lead thyroid shield in limiting the radiation dose to the thyroid gland. In addition we undertook a questionnaire of orthopaedic surgeons and trainees in Ireland to assess the availability of thyroid shields and current practice in wearing them.

Method A total of 30 cases were evaluated. Dosimeter film badges (TLD) were obtained from the Radiological Protection Institute of Ireland (RPI). Two dosimeters were worn by each of the surgical team: one on the dorsum of the dominant hand and a second worn on the neck during the procedure. The number of fluoroscopic exposures, number of times that hands were caught in the image field, the total dosage of radiation for the procedure and the length of time of exposure were recorded. In 20 cases the surgical team undertook standard precautions of a lead jacket. In a random selection of 10 cases the surgical team also wore a thyroid shield.

Results. The mean dose to the surgical teams’ hands was 1.8 cGy (95% CI + 0.6). The mean dose to the thyroid gland was 0.6 cGy in unprotected cases. Notably the dose to the assistants’ hands was higher though this did not reach statistical approval. In cases in which a thyroid shield was worn a significant decrease in dose was noted (p< 0.05). 35% of surgeons had completed a radiation protection course with junior trainees being less likely to have completed such a course.

Conclusion: Significant cumulative radiation dose to the hands and thyroid gland occurs following K-wiring of extremities. The dose to the thyroid gland can be effectively decreased by the use of a thyroid collar. Junior trainees whose operative times and hence radiation exposure are higher, have limited radiation protection training. The mandatory use of thyroid shields and early introduction of radiation protection training may help minimise further radiation exposure.

Introduction: Despite exhaustive prophylactic measures, intra-operative contamination still occurs following cemented arthroplasty. We undertook a prospective study to identify the incidence of intra-operative deep wound contamination in cemented joint arthroplasty. Furthermore, we assessed the medium term incidence (at 4 years) of wound contamination in this patient cohort.

Materials & Methods: A total of 82 consecutive patients admitted for elective cemented arthroplasty were enrolled in the study over a 6 month period. Standard medical and dental work up was performed prior to admission to assess fitness for surgery. Pre-operative wound site preparation included Hibitane showers and painting and draping of the operative site in both the anaesthetic room and theatre. All cases were undertaken in an ultra-clean laminar airflow theatre and the surgical team wore isolation suits in all cases. Standard swabs from skin incision and deep in the wound were sent in addition to the blades and suction tip used. Cultures were typed by morphology and identified by standard techniques. A control swab was sent from all cases to exclude contamination occurring in the laboratory setting.

Results: A total of 82 patients were included in the study. Mean patient age was 67.4 years (36–85 years). Of the 82 procedures performed, 59 were total hip replacements and 23 total knee replacements. Five procedures were performed for revision arthroplasty (1 knee and 4 hips). 19 of the 82 cases (23%) examined grew contamination organisms with S. epidermidis being the commonest organism (16). In 16 cases a single specimen demonstrated contamination. 2 patients had 2 contaminated specimens and 1 had 3 contaminated specimens. No significant correlation between the duration of the case, number of personnel in theatre, or the seniority of the operating surgeon was demonstrated. On medium term follow up (mean 49.6 months, 95% CI 3.2 months) no patient had developed clinical evidence of infection.

Conclusion: We noted a high incidence of intra-operative contamination of cemented arthroplasties despite standard prophylaxis. However, this was not reflected by a similar rate of post-operative infection. This may be due to a small bacterial innoculum in each case or possibly may be due to the therapeutic effect of peri-operative intra-venous antibiotic prophylaxis.

Introduction: Proximal humeral fractures are common in the elderly osteoporotic population. Surgical management of such fractures with traditional internal fixation techniques is often challenging due to poor bone quality. Fixation with intramedullary devices theoretically offers better fixation, but with increased risk of shoulder pain and decreased range of motion. We undertook a study to compare outcome following fixation of such fractures with either an intramedullary nail (Polarus), standard Clover Leaf plate (AO), or Philos Locking plate (AO).

Method: All patients admitted for surgical management of a proximal humeral fracture were entered into the study. 10 patients were treated using a Philos plate (Group 1), 5 with a Clover Leaf plate (Group 2), and 10 with a Polarus nail (Group 3). Post-operative assessment included radiological evaluation, clinical assessment of range of motion compared to the non-injured arm, assessment of pain severity (visual analogue scale), and functional assessment (DASH score). Non-parametric statistical techniques were used to analyse results.

Results: There was no significant difference in age or sex distribution between the three groups. (Mean ages: Group 1: 54.6 yrs, Group 2: 45.2 yrs, Group 3: 59.7 yrs) Mean patient follow-up was 22 months (range 5–52 months).

All patients in Group 1 and 2 went on to satisfactory radiological and clinical union. A higher complication rate was noted in the Polarus nail group, with 3 patients requiring removal of metal due to soft tissue or subacromial impingement. In addition one patient developed a non-union and required Philos plate fixation.

All groups demonstrated a significant decrease in shoulder range of motion following injury, however this was less marked in Group 1 (Philos plate). In addition, patients in group 1 (Philos plate) demonstrated a more rapid recovery in terms of severity of pain, functional impairment and range of motion in the early postoperative phase. However, no significant long-term difference was noted in terms of post-operative pain or functional deficit between group 1 and 2. The poor outcome in group 3 was associated with a high incidence of shoulder pain and secondary procedures.

Conclusion: Intramedullary fixation of proximal humeral fractures resulted in a high level of complications requiring secondary procedures in many cases. Our study supports the safety and efficacy of plate fixation techniques in the operative management of proximal humeral fractures.

Introduction: With a worldwide aging population, and an expected doubling in numbers of people older than 65 between 1990 and 2020, we are in the midst of a predicted increase in osteoporosis and resultant fractures. The International Osteoporosis Foundation recently surveyed consultant orthopaedic surgeons in mainland Europe and New Zealand to determine how patients with osteoporotic fractures were managed. Their conclusion was that treatment patterns were varied, and the findings supported the need to improve fragility fracture services to reduce the risk of recurrent fractures.

Aim: The aim of our study was to see how Irish practices and opinions related to the IOF survey, in anticipation of a formal protocol being established in our unit.

Methods: A modification of the International Osteoporosis Foundation survey used in 2002 was sent to 85 Consultant Orthopaedic Surgeons listed in the Irish Medical Directory. The questionnaire evaluated the surgeon’s education and knowledge of osteoporosis management, as well as estimated numbers of patients being treated with osteoporosis and the investigations available to their service. Treatment and referral patterns were also established. All responses were anonymous.

Results: The Irish response rate to the survey of nearly 50% was higher than that of our European colleagues, and showed that only 25% of surgeons felt they received sufficient training in the area of osteoporosis, but only a minority were not confident managing the disease. One-quarter of those surveyed would treat a patient with a fragility fracture for osteoporosis themselves, while over half would refer the patient on to a General Practitioner for further management. 50% of Irish Consultants would first order bone mineral densitometry, and nearly three-quarters believe the General Practitioner is the most appropriate professional to follow up these patients. Significantly, 15% of Orthopaedic surgeons did not have any access to densitometry. The most popular treatment modality is a combination of calcium and vitamin D supplementation in conjunction with Alendronate.

Conclusion: There is currently a lack of standarisation in the management and follow up of patients with osteoporosis. While the disease and its treatment is an internationally important topical issue, our study showed that at a national level there is a lack of consistency between the need for specialised services and implementation of treatment algorithms, due in part to lack of investigative facilities and organised management teams.

Background: Interest is growing in minimally invasive techniques to treat vertebral fractures in the elderly population. Amongst the benefits mooted are relief of pain and prevention of deformity. However little background data is available concerning the long-term outcome of such patients treated by either conservative or surgical means.

Aim: To describe the natural history of a cohort of patients with osteoporotic vertebral fractures, treated conservatively with bedrest and a Taylor brace.

Patients and Methods: All patients admitted to our institution over a five-year period following a vertebral fracture were identified. A total of 223 patients were admitted over the study period. Of these, 61 were suitable for inclusion in the study. Following departmental approval all patients were contacted by phone and invited to participate in the study. Patients were examined in the clinic, plain radiographs were performed and the Oswestry pain score, a visual analogue pain score (VAS), and SF36 questionnaire were completed.

Inclusion criteria: Patients over 65years at time of injury

Minor trauma e.g. minor fall

No neurological deficit

Exclusion criteria

Patients over 65years who were involved in major trauma.

Non-Irish residents.

Results: Mean patient age at the time of injury was 72.1years. Mean duration of follow up was 8.2 years with a minimum follow up of 5 years. Seven patients were lost to follow up. Of the remaining fifty-four patients, five had died since their admission. According to family members none had any pain or neurological symptoms related to their backs. Forty patients attended the clinic for review while nine completed telephone questionnaires.

On examination two patients had a clinically evident kyphosis. The mean range of anterior flexion was 78.9° + 15°. The mean VAS pain score was 2.2 + 2.0. No significant correlation existed between the magnitude of the initial vertebral collapse and the Oswestry or SF36 scores. No significant further vertebral collapse was noted on radiographic follow up. A small cohort of patients did develop chronic back pain. These patients’ outcome could not be predicted on the basis of initial radiographs.

Discussion: Our study supports conservative management: most patients recovered normal function and suffered little long-term pain. It was not possible to predict which patients would develop chronic back pain on the basis of initial radiographs. This calls into question the indications for undertaking vertebroplasty or kyphoplasty in the treatment of such patients.

Aim: The literature suggests that the incidence of osteomyelitis in the paediatric population has changed. We undertook to examine changes in incidence, causative organisms and treatment regimes over a 13 year period.

Methods: Patients admitted with a diagnosis of osteomyelitis between January 1991 and January 2004 were identified from hospital records and data collected from their medical and laboratory records.

Results: A total of 362 patients were admitted over the study period with a mean age of 5.9 years. A significant decrease in the number of patients presenting over the study period with osteomyelitis was noted, from a peak of 77 cases in 1991 to 12 cases in 2003 (p< 0.05). There was no significant difference in patient age or length of hospital stay over the study period. The majority of cases involved the lower appendicular skeleton with Staphylcoccus Aureus being the commonest organism cultured (accounting for 60% of positive cultures). All cases were initially treated empirically with intravenous Flucloxicillin and oral Fusidic acid. Surgical debridement/decompression was required in 11% of cases.

Conclusion: Osteomyelitis now appears to be a rare condition in children with a marked decrease in the incidence being noted over the study period. This correlates with the introduction of the Haemophilus Influenzae B vaccination in Ireland and may partly explain the decrease in incidence. The majority of cases settled on a course of non-operative management.

Introduction: The meniscus plays an important role in protecting the articular surfaces of the tibia and femur from excessive wear due to aberrant forces across the knee joint. While the biochemical changes associated with cartilage and meniscal wear have been well documented, little data exists in the literature describing the ultrastructural events associated with such a degenerative process.

Aim: To develop an in vivo model to evaluate the effects of joint incongruity on meniscal wear.

Materials and Methods: Six New Zealand White rabbits underwent an arthrotomy of the right knee joint. A sagittal osteotomy of the medial femoral condyle was then performed on four of these animals while the remaining two served as controls. Post operatively all animals were allowed to mobilise ad librium and were sacrificed after 20 weeks. The medial meniscus was harvested and processed for electron microscopy by routine methods. Survey light microscopy sections (1um) were examined and adjacent ultra-thin sections (50nm) were assessed in an electron microscope at magnifications from 1,500 to 30,000.

Results: On gross examination of the menisci there was no evidence of any significant wear. Neither was there noticeable damage on light microscopy. There was no significant difference in the numbers of chondrocytes and fibroblasts in the superior and inferior surfaces of both control and test samples, indicating a lack of cellular response in the test specimens. On electron microscopy, the superficial electron dense layer was markedly attenuated in test subjects (control 246 – 305 nm, test 109 – 167nm). The superior surfaces of two test samples were markedly roughened, while chondral fragments were noted in craters on the surface. Numerous cystic lesions were present within the superficial collagen stroma of test subjects. Interestingly cleavage planes were noted in the superior and inferior aspects of one of the four test subjects. No difference in collagen fibril diameter was observed between control and test subjects.

Discussion: These results represent the early stages of meniscal degeneration. The process appears to one of microfibrillation, with degeneration occurring within the bundles of collagen fibrils rather than within the substance of the fibrils themselves. The absence of a healing response suggests that this is an intractable process, a finding which accords well with findings in the clinical setting.

Introduction: The magnitude of the initial chondral injury and the residual articular step-off are amongst prognostic factors implicated in outcome following intra-articular fractures. The alignment of an intra-articular fracture line may be an as yet unrecognised prognostic variable.

Hypothesis: That fractures in the coronal plane of the medial femoral condyle result in worse outcomes than those in the sagittal plane.

Aim: To compare the effect of displaced intra-articular osteotomies (ie simulating fractures fixed in an incongruent position) of the medial femoral condyle – in one group performed in the sagittal plane, in the other in the coronal plane.

Materials and Methods: The study was conducted in two arms: in vitro and in vivo.

In vitro study: A pneumo-electric rig was designed and built. Ten freshly harvested porcine knee joints underwent osteotomy (test specimens: 5 sagittal, 5 coronal). 5 control specimens underwent no osteotomy. Specimens were mounted on the rig and subjected to cyclical flexion and extension under load (40,000 cycles over 11 hours). Transarticular pressure measurements were performed before and after testing. Surface roughness was measured following testing using laser interferometry.

In vivo study: Three groups (A to C), each comprising 15 New Zealand white rabbits were utilised. Rabbits from each group were consigned to a control (5), coronal osteotomy (5) or sagittal osteotomy (5) group. Rabbits in group A were sacrificed at 3 weeks (early outcome), group B at 10 weeks (immediate) and group C at 20 weeks (long term). The knee was then harvested en bloc and prepared for light microscopy. A further 10 specimens underwent electron microscopy of the medial meniscus.

Results:

In vitro study: A significant difference in loading patterns was noted between the sagittal, coronal and control groups. Specimens from the sagittal group sustained significantly more wear on the apposing medial tibial articular surface (p=0.04), with the meniscus having a protective effect on the underlying articular surface.

In vivo study: Light microscopy confirmed degenerative changes in the apposing tibial articular cartilage, being more marked in sagittal specimens. On the femoral side of the knee, the healing response of the femoral osteotomy was significantly better in sagittal test specimens than coronal (p< 0.05).

Conclusion: In contrast to the hypothesis, sagittal femoral step-offs gave rise to more tibial wear. This can be explained by the short duration of exposure of the coronal incongruity to the apposing joint during the flexion extension cycle. The sagittal step-off was constantly exposed, giving rise to persistently elevated tibial joint loading pressures opposite the high side of the step-off.

In contrast, the coronal femoral osteotomies had a worse healing response. The alignment of the fracture line perpendicular to the plane of motion of the joint exposes the repair tissue within it to increased shear and tensile stresses. This may play a negative role in the repair of these coronal defects when compared to sagittal osteotomies, which are relatively protected from the high transarticular pressures and showed a greater tendency to remodel their articular surface.

Introduction: Recent data from the UK suggests that the incidence of osteomyelitis in the paediatric population is declining. However, the incidence in the Scandic countries has risen in the late eighties and nineties. We undertook to examine the epidemiology of osteomyelitis presenting to a paediatric teaching hospital in an Irish urban setting.

Patients and Methods: We undertook a retrospective review to identify patients admitted over a twenty-five year period with a diagnosis of osteomyelitis. Patients were identified from hospital records, theatre log-books and a departmental database. Demographic data was collected, as were details of the infected bony structure, treatment required and organism cultured.

Results: A total of 291 patients were admitted over a twenty-four year period, from 1977 to 2000.

A marked reduction in osteomyelitis was noted over the twenty-four year incidence of the study. In addition, a shift in the causative organism was noted from an incidence of H Influenzae in the 70’s of up to 30%, to less than 5% in the 90’s. The treatment regime changed markedly over the course of the study period, with a significantly reduced duration of hospital stay reflecting the move away from protracted periods of hospitalisation.

Conclusion: A marked fall in osteomyelitis has occurred in the paediatric population. This may be due to improved living conditions and the introduction of H Influenzae vaccinations. The duration of hospital stay has declined markedly and the introduction of newer imaging modalities has aided diagnosis, allowing early aggressive intervention. However, as osteomyelitis is becoming increasingly rare, a higher index of suspicion is required, particularly from non-specialists who are more likely to be the first to encounter these patients.

Introduction: Good outcome following traumatic injuries of the thumb ray depends upon obtaining and maintaining anatomical reduction. Traditional methods using percutaneous Kirschner wires often yield poor results in complex injuries. The Stockport Serpentine Spring System, or “S” Quattro, was developed to achieve and maintain fracture reduction by ligamentotaxis. Distraction reduces fracture fragments due to the tension of ligamentous and structures surrounding the injured joint.

Methods: Ten patients with thumb fractures were treated with the “S” Quattro external-fixation device over a seven-year period from 1996–2003. The operative technique as described by Fahmy was employed. The fixation device was applied for 3 to 7 weeks.

Results: Of the 10 patients, 8 were male and 2 female, and their mean age was 28.9 (range 18–46). Injuries were sustained through sports injuries (6), falls (2) and road traffic accidents (2). Half of the patients were referrals from other orthopaedic units, three of these having failed conservative management. Injuries included 2 Rolando fractures, 5 closed, comminuted metacarpal fractures, 1 open, comminuted fracture and 1 fracture subluxation of the carpometacarpophalangeal joint. Mean interval to treatment was 8.1 days (range 2–15 days). Patients were followed for an average of 8.3 months (range 3–25 months). The mean total range of motion at discharge for the affected joint was 130 degrees. Two patients described subsequent joint pain and stiffness, one developed complex regional pain syndrome. Of note, this patient had a synchronous fracture of the distal humerus. Overall, most patients expressed high outcome satisfaction with mean DASH (Disability of the Arm, Shoulder and Hand) scores of 31.4.

Conclusion: The “S” Quattro dynamic external –fixation device proved to be effective in the management of intra-articular fractures of the first ray. The fixator achieved good functional results with an acceptably low complication rate. We propose that this device is superior in maintaining anatomical reduction of these comminuted fractures than traditional methods such as Kirschner wiring.

Study Design: Prospective Cohort Study.

Objective: To describe the natural history of a cohort of patients with osteoporotic vertebral fractures treated conservatively with bedrest and a Taylor brace.

Summary of Background Data: Interest is growing in minimally invasive techniques to treat vertebral fractures in the elderly population. Amongst the benefits mooted are relief of pain and prevention of deformity. However limited background data is available concerning the long-term outcome of such patients treated conservatively.

Patients and Methods: All patients admitted to our institution over a five-year period following a vertebral fracture were identified (n=223) Of these, 61 were suitable for inclusion in the study. Following departmental approval all patients were contacted by phone and invited to participate in the study. Patients were examined in the clinic, plain radiographs were performed and the Oswestry pain score, a visual analogue pain score (VAS), and SF-36 questionnaire were completed. Patients over 65 years, involved in minor trauma without neurological deficit were included. Patients over 65 years who were involved in major trauma or non-Irish residents were excluded from the study.

Results: Mean patient age at the time of injury was 72.1 years. Mean duration of follow up was 8.2 years with a minimum follow up of 5 years. Seven patients were lost to follow up. Of the remaining fifty-four patients, five had died since their admission. According to family members none had any pain or neurological symptoms related to their spinal injuries. Forty patients attended the clinic for review while nine completed telephone questionnaires. Two patients had a clinically evident kyphosis. The mean range of anterior flexion was 78.9° ± 15°. The mean VAS pain score was 2.2 ± 2.0. No significant correlation existed between the magnitude of the initial vertebral collapse and the Oswestry or SF-36 scores. Physical Function and Bodily Pain subsets of SF-36 were no different to an age matched Irish population. No significant further vertebral collapse was noted on radiographic follow up. A small cohort of patients did develop chronic back pain. These patients’ outcome could not be predicted on the basis of initial radiographs.

Conclusion: This study supports conservative management: most patients recovered normal function and suffered little long-term pain. It was not possible to predict which patients would develop chronic back pain on the basis of initial radiographs. This calls into question the indications for undertaking vertebroplasty or kyphoplasty in the treatment of such patients.

Introduction: Our institution is a stand-alone elective orthopaedic unit. The majority of prospective arthroplasty patients undergo in-patient pre-operative assessment.

Aim: We assessed the efficacy of a consultant physician delivered pre-operative assessment clinic for patients undergoing elective hip arthroplasty in terms of financial costs, duration of stay, cancellation rate and postoperative complications.

Patients and Methods: A study was undertaken over a six-month period comparing two age and sex matched patient cohorts. Group 1 consisted of 40 patients who were admitted directly for hip arthroplasty, while Group 2 patients were admitted for in-patient assessment prior to being readmitted for surgery. Data collected included patient age, presence of comorbidities. ASA score and the presence of post-operative complications.

Results: Group 1 comprised 40 patients with a mean age of 62.7 years (51–70), while Group 2 included 50 patients whose mean age was 63.78 years (51 – 70). A majority of patients in both groups were male. A significantly lower number of comorbid conditions and a lower ASA score were noted in group 1 patients, when compared with group 2. In addition, a shorter duration of hospital stay was noted in Group 1 patients with an associated decrease in costs.

Only one patient (2.5%) from Group 1 was cancelled pre-operatively; this for treatment of a chronic comorbidity. Five patients (10%) in Group 2 were cancelled on admission for surgery. Four of these patients were cancelled for acute illness that had developed following in-patient assessment, with one being discharged for treatment of a chronic illness.

Discussion: In-patient assessment prior to joint replacement placed a considerable burden on patients and healthcare resources. Patients referred to the assessment clinic were sicker, had a longer duration of hospital stay and had a higher incidence of cancellations than their peers in Group 1. It is important to note that the majority of all cancellations were due to the presence of acute medical problems not present at the time of assessment. Thus we feel that the current practice of in-patient assessment is financially inefficient and does not produce a notable decrease on pre-operative cancellations. In our opinion it is better replaced with an anaesthetic assessment on an out patient basis.

Background: The total cost of a joint arthroplasty is a matter of increasing interest to health economists. Patients who are admitted for elective procedures and subsequently cancelled incur significant additional costs and prevent admission of other patients.

Aim: We undertook a study to examine the incidence, causes and costs associated with pre-operative cancellation in an elective orthopaedic unit.

Patients and Methods: We reviewed all orthopaedic admissions over a twenty-month period, from March 2000 to June 2002. A total of 1,220 patients were admitted for arthroplasty. 62 patients (5.1%) were cancelled pre-operatively following admission. Detailed analysis of these cases was then undertaken, with details and costings of ancillary investigations obtained from relevant laboratory and radiology departments.

Results of Cancelled Patient Cohort: Mean patient age was 71.5 years (versus 75.3 yrs for non-cancellations) with a slight female preponderance. Almost three quarters of cancellations (72.5%, 45 patients) were avoidable, subsequently having their procedure at a later date. The remaining seventeen patients had chronic comorbidities and were judged permanently unfit for surgery following further work up. Of the 45 deferred patients, 16 patients were postponed to allow optimization of comorbid conditions. 19 patients had their surgery delayed for acute illnesses that had developed in the fortnight prior to admission. Infection was the commonest cause of cancellation in this group (n=18), with one patient cancelled due to a pre-operative DVT. The residual 10 patients were cancelled due to improvement of symptoms (4) unavailability of blood (3), anaesthetic equipment failure (2), and patient wishes (1). A comparison was performed using Student’s t test between patients temporarily deferred or permanently cancelled on the basis of age, comorbid conditions, ASA score and duration from in-patient assessment to admission. Only ASA scores demonstrated a significant difference between the two groups (Deferred 2.39, Cancelled 2.92; p< 0.01). The mean cost per admission was €10,187.26 with “Hotel” costs forming up to 75% of the total. While patients who were operated on inevitably incurred significantly higher costs (p< 0.01) it is noteworthy that the mean cost of admission per cancelled patient was €4,531, amounting to €77,010 over the study period. In addition, patient whose surgery was deferred incurred significant extra costs when compared with uncomplicated cases (mean excess €1,867). Therefore the additional costs of these 63 patients amounts to a total of €161,025.

Conclusion: Patients cancelled following admission incurred considerable costs. In order to minimize costs and maximize efficiency, we would recommend that the small cohort of patients with a high ASA score have a focused anaesthetic review pre-operatively. A program of education directed at patients and general practitioners would help eliminate minor illnesses, which necessitate cancellation, prior to admission.

Background: Interest is growing in minimally invasive techniques to treat fractures in the elderly population. Amongst the benefits mooted are relief of pain and prevention of deformity. However little background data is available concerning the long-term outcome of such patients treated by either conservative or surgical means.

Aim: To describe the natural history of a cohort of patients with osteoporotic vertebral fractures treated conservatively with bed rest and a Taylor brace.

Patients & Methods: All patients admitted to our institution over a five-year period following a vertebral fracture were identified. A total of 223 patients were admitted over the study period. Of these, 61 were suitable for inclusion in the study. Following departmental approval, all patients were contacted by phone and invited to participate in the study. Patients were examined in the clinic, plain radiographs were performed and the Oswestry pain score, a visual analogue pain score (VAS), and SF36 questionnaire were completed.

Inclusion Criteria:

Patients over 65years at time of injury

Minor trauma e.g. minor fall

No neurological deficit

Exclusion Criteria:

Patients over 65 years who were involved in major trauma.

Non-Irish residents

Results: Mean patient age at time of injury was 72.1years. Mean duration of follow up was 8.2 years with a minimum follow up of 5 years. Seven patients were lost to follow up. Of the remaining fifty-four patients, five died since their admission. According to family members, none had any pain or neurological symptoms related to their spinal injuries. Forth patients attended the clinic for review while nine completed telephone questionnaires. On examination, two patients had a clinically evident kyphosis. The mean range of anterior flexion was 78.9 + 15. The mean VAS pain score was 2.2 + 2.0. No significant corrleation existed between the magnitude of the initial vertebral collapse and the Oswestry of SF36 scores. No significant further vertebral collapse was noted on radiographic follow up. A small cohort of patients did develop chronic back pain. These patients’ outcome could not be predicted on the basis of initial radiographs.

Discussion: Our study supports conservative management: most patients recovered normal function and suffered little long-term pain. It was not possible to predict which patients would develop chronic back pain on the basis of initial radiographs. This calls into question the indications for undertaking vertebroplasty or kyphoplasty in the treatment of such patients.

Introduction: Outcome following intra-articular fractures is dependent on a myriad of variables, including the extent of the initial osteochondral and soft tissue injury. In the clinical setting it is impossible to control such variables, and studies are largely confined to radiographic and outcome based assessments. Therefore the effect of fracture line orientation has not been widely examined. Theoretically an incongruent intra-articular fracture results in a “low” side that is relatively unloaded, at the expense of a “high” side exposed to increased loads. Furthermore the orientation of the fracture may give rise to a narrow or broad swathe of wear on the opposing articular surface.

Aim: To evaluate the effect of an incongruent intra-articular fracture of the medial femoral condyle on subsequent loading and wear patterns, using an in vitro model.

Materials and Methods: 15 porcine stifle (knee) joints were harvested within three hours of death. Three groups of five joints were evaluated. Group S underwent a sagittal osteotomy of the medical femoral condyle that was then fixed in an incongruent position. In Group C the osteotomy was performed in the coronal plane. The third group acted as a control group and had no oseotomy performed. In all cases great care was taken to prevent injury to the menisci, articular surfaces and Ligamentous structures. The size of the step-off was documented using a contour-mapping machine (CMN). In addition the surface roughness of the femoral condyles was documented using a laser interferometry device (UBM, Germany). The specimen was mounted on a custom-made electro-pneumatic rig, and pressure mapping of the articular surfaces performed with pressure sensitive film (SPI, New Jersey, USA). Following mapping, each specimen underwent 10,000 cycles of flexion and extension over a three-hour period. When testing was complete, pressure mapping was again performed, the size of the step-off re-measured using the CNM, and surface roughness of the menisci, femoral condyles and tibial plateau assessed. Data was restored on a laptop for subsequent statistical analysis.

Results: Pressure mapping documented an unloaded area on the low side of the step-off in both Group C and S. This extended up to 8mm, and was mirrored by an area of increased load on the high side. Following testing, the area exposed to altered loads on both the high and low side of the osteotomy had diminished. On ANOVA testing the uncovered tibial articular surfaces in test subjects were significantly rougher than control specimens, though no difference was noted between Groups C and S (Mean Ra value GC: 101.83+22.78, GS: 93.52+17.89, ns. vs. Con 53.45+25.8,p< 0.05). Meniscal surface roughness was greater in the test groups, though this did not reach statistical significance. No significant difference in femoral condyle surface roughness was noted following testing. Nor was any difference noted in surface roughness in the submeniscal areas of the tibial articular surface.

Discussion: The displaced femoral osteotomy resulted in an area of increased wear on the opposing tibial articular surface. However no significant difference was noted between the coronal and sagittal group. It is probable that the menisci negated the effect of fracture line orientation. We suggest that they minimized secondary articular damage by decreasing the area of direct tibiofemoral contact. Furthermore the elasticity of the menisci, in addition to their ability to move in the anteroposterior plane further decreased stress transmission between joint surfaces. Further studies will be performed on the hip joint to determine the effect of articular incongruity in the absence of such a fibrocartilage buffer.

Introduction: Operative fixation is the mainstay of treatment for displaced ankle fractures. Results however can be variable, with patients complaining of residual pain and stiffness of the ankle joint. In addition, metalwork can be problematic giving rise to symptoms in up to 25% of patients. We undertook a retrospective study to evaluate outcome in terms of functional and radiological criteria in a cohort of patients.

Aim: To assess outcome in a cohort of patients following operative treatment of ankle fractures.

Materials and Methods: Patients with suitable injuries sustained were identified from the hospital HIPE database. Data was collated from hospital records including demographic details, mechanism of injury, details of the initial injury and surgical treatment. Patients were invited to attend for clinical and radiological examination of the injured ankle. Patients completed the SF12, the Olerud ankle score and a visual analogue pain scale (VAS) on arrival at the clinic. The range of motion of both the injured and uninjured ankle were examined. Finally, the patient’s injured ankle was evaluated on plain X-rays using Cedell’s scoring system. Comparison was made with initial roentgens at the time of injury.

Results: From 106 patients treated over a four-year period, 63 were successfully followed up. Mean time of follow up was 3.5 years. Older patients had a poorer recovery, as had those with more severely displaced fractures. Pain was not a major problem for patients with 58 complaining of no pain, or pain only after prolonged exercise. 43% of patients complained of occasional swelling of the affected limb. The majority of patients (89%) had returned to their previous occupations at the time of follow up. 16% of patients (10) had their metalwork removed post operatively. In seven cases, this was due to skin problems or pain adjacent to the metalwork.

Conclusion: Older age at presentation, and severity of initial injury appear to have a significant effect on long-term outcome, which may be attributable to poorer osteosynthetic ability in an elderly osteoporotic patient. Our study underlines the importance of accurate anatomical reduction of ankle fractures in order to minimise subsequent arthrosis.

Introduction: Since the introduction of joint arthroplasty major advances including the introduction of laminar airflow, have been made in reducing infection to current rates of 1 to 2%. Nonetheless infection remains a devastating complication, with major implications in terms of patient suffering, duration of hospital stay and financial burden. We undertook a study to examine the incidence of bacterial wound contamination occurring in the intra-operative period.

Materials and Methods: All patients admitted to our unit for elective hip and knee arthroplasty were entered into the study. On arrival in theatre a skin swab was taken. The patient was then prepared and draped in the anaesthetic room before final draping by the surgical team in the operating theatre. All procedures were performed in theatres equipped with laminar airflow, and all surgical personnel wore isolator suits. During the course of the procedure swabs were taken from the anterior aspect of the femur at 30-minute intervals. In addition the skin and inside blades and the suction tip were harvested at the end of the procedure. All samples were then sent for culture. Patient data including age, comorbid conditions and history of previous surgery were noted on a standardised pro forma. In addition, operative data including duration of the procedure, operating surgeon and type of drape and skin preparation used were noted.

Results: 65 patients have been examined to date. An incidence of contamination of 14% has been noted (9 patients) with the skin blade and suction tip being the most common source of contaminating organisms. Staphylococcus epidermis was cultured in 5 cases, with Gram negative organisms being cultured in the remaining samples. In all 9 cases only small numbers of organisms were identified. None of the patients with positive cultures developed clinical signs of deep or superficial wound sepsis, and all had an uncomplicated postoperative course.

Conclusions: While low levels of contamination are unavoidable in theatre, it is important that strict discipline be maintained in order to minimise this risk. In particular, careful attention to patient skin preparation, the use of prophylactic antibiotics and minimising use of the suction tubing help decrease contamination rates.

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.