INTRODUCTION

Femoral stem impingement can damage an acetabular liner, create polyethylene wear, and potentially lead to dislocation. To avoid component-to-component impingement, many surgeons aim to align acetabular cups based on the “Safe Zone” proposed by Lewinnek. However, a recent study indicates that the historical target values for cup inclination and anteversion defined by Lewinnek et al. may be useful but should not be considered a safe zone. The purpose of this study was to determine the effect of altering femoral head size on hip range-of-motion (ROM) to impingement.

Introduction

It is recommended that the ankle be held in dorsiflexion at the time of placement of syndesmosis screw. We assessed the validity of this recommendation.

Purpose: To determine whether generalized ligamentous laxity is a predisposing factor for primary traumatic anterior shoulder dislocation in young, active patients.

Method: Prospective case series with age and sex matched controls. The Hospital Del Mar Criteria was utilized to measure generalized ligamentous laxity. Fifty-seven (n=57) consecutive individuals (age< 30) sustaining a primary traumatic anterior shoulder dislocation between 2003 and 2006 were examined for hyperlaxity. The control group was comprised of seventy-two (n=72) undergraduate university students without a prior history of shoulder dislocation or anterior cruciate ligament injury.

Results: After adjusting for age and sex, the prevalence of hyperlaxity in the study group was 32.8% compared with 10.4% in the control group (p< 0.01). The prevalence of increased contralateral shoulder external rotation (> 85o) was 40.3% in the study group compared with 20.8% in the control group (p< 0.03). Among males, the prevalence of hyperlaxity was 28.3% in the study group and 5.3% in the controls (p< 0.01).

Conclusion: Although several studies have looked at the variables affecting shoulder instability, generalized ligamentous laxity (as measured by validated criteria) has not previously been identified as a predisposing factor for primary traumatic shoulder dislocation. This study demonstrates that generalized joint laxity and increased external rotation in the contralateral shoulder were found to be more common in patients who had sustained a primary shoulder dislocation. These observations may suggest a role for shoulder-specific proprioceptive and strength training protocols in hyperlax individuals participating in high-risk sports. Furthermore, the implications of hyperlaxity on the surgical management of traumatic primary shoulder instability are uncertain.

Purpose: Traumatic knee dislocations are complex injuries. A thorough knowledge of the pattern of ligament damage is essential to plan for definitive treatment. Injuries to the structures of the posteromedial corner (posterior oblique ligament, the semi-membranosus tendon and its expansions, the meniscofemoral and meniscotibial ligaments, posterior horn of the medial meniscus and posterior reflections of the deep and superficial medial collateral ligament) can contribute to rotational laxity and have not been previously described in the setting of knee dislocations. We set out to evaluate the injury patterns of the posteromedial corner in a series of traumatic knee dislocations.

Method: A radiographic (MRI) study was conducted on 22 multi-ligament knee injuries in 22 patients, managed at a level one trauma centre by a single surgeon between July 2006 and May 2008.

Results: There were 14 male and 6 female patients with an average age of 29. The mechanism of injury was high velocity in 10 cases, and low velocity in 12 cases. One case (ACL/PCL/posterolateral corner injury) was associated with a vascular injury. While the incidence of MCL injury was 59%, injury specific to the PMC was evident on MRI in 81.8% (18/22) of cases. The deep and superficial MCL were involved in 13/18 and 12/18 PMC injuries, respectively. The posterior oblique ligament was injured in 11/18 cases and the semi-membranosus and its expansions were injured in 10/18 cases (all distal). Injuries to the posterior horn of the medial meniscus (9/18 cases) were associated with a tear of the menisco-femoral/meniscotibial ligaments in all cases.

Conclusion: Injury to the PMC was common with high-grade multi-ligament knee injuries in this series. PMC injuries were more common than MCL injuries alone. Injury to the posterior horn of the medial meniscus was predictive of more extensive PMC injury in all cases. The posteromedial corner of the knee is an under recognized area where important injuries can occur in the setting of a dislocatable knee. Future research will involve the correlation of the injury patterns described in this series to clinical measures of knee instability and laxity.

Background: Unicondylar knee arthroplasty (UKA) are being expanded to include younger patients with more active lifestyles because of its minimally invasive nature. Prior to expanding this role, it is important to examine mode of failure and implication of conversion to TKA in the low demand elderly patients.

Aim: To ascertain the modes of early failure of unicondylar knee Arthroplasty and assess whether the conversion to TKA improved the functional scores, range of motion, pain, and patient satisfaction.

Method: A retrospective study to evaluate the results of 14 revision procedures after failed unicompartmental knee arthroplasty (UKA). Patients’ operative charts were reviewed. Details of modes of failure, technical difficulty of revision including exposure, component removal, and management of bone loss were noted. Post operative functional outcome was assessed using WOMAC osteoarthritis index and SF-36.

Result: Total of 106 primary unicondylar knee arthroplasty procedures was performed between 2003 and 2007 in our institution. Oxford unicondylar implant was used in all patients. 13.21% of these were revised to total knee replacement. Revisions were performed 4 months to 36 months after the primary procedure; 86% of these were required within the first 12 months. The average time to failure was 15.6 months.

The modes of failure were aseptic loosening (4), progression of osteoarthritis (2), instability (3), infection (2), dislocated insert (1) and persistent pain after UKA (2). Tibia insert exchange was done in one patient and the rest were converted to primary Scorpio and PFC components. Three of the patients had significant defect in femoral condyle. Fourteen percent of cases required femoral stem extension or metal wedge augmentation.

Nine of the 14 knees (64%) were followed up for an average of 15 months. The mean WOMAC and SF-36 scores at latest follow up were 33.33 and 63.79 respectively.

Conclusion: Despite the advantage of minimally invasive UKA, early failure can occur in the face of good surgical technique. The higher long-term success rate claimed by implant manufacturer is challengeable and patient should be informed during consent.

Introduction: In clinical practice The Cascade sign is widely used to assess the rotational deformity of the fingers associated with metacarpal and phalangeal fractures. We carried out a scientific study on thirty volunteers to evaluate the validity or otherwise of this standard sign.

Material and Methods: Metal pointers were attached to the dorsum of the fingers, flexed at MCP and PIP joints. These pointers represented the mid longitudinal axis of the phalanges. Standardised AP radiographs of the closed fist were taken in all cases with the wrist placed in neutral position, in a custom made jig. The radiographs were assessed by two different observers using Picture Archiving and Communication System, software version VA42B, to determine the convergence of the metal pointers towards the scaphoid tubercle, as described in the cascade sign and Lister method..

Statistics: Power of the study was determined with an assumption of a type-2 error of 0.05 and a two sided test. Descriptive statistics and confidence limits were calculated using SPSS 11 software.

Results: We observed that the metal pointers did not equivocally converge towards the scaphoid tubercle. The persistent pattern of convergence was within a 2–3cm radius of the scaphoid tubercle. The statistical analysis, two tailed paired t-test of this pattern showed strong association with this latter finding. (p< 0.003).

Conclusion: Our study suggests that the cascade sign is sensitive but not specific to access the rotational deformity of the fingers. Radiological there is significant scatter about the scaphoid tubercle.

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: Bone Morphogenic Proteins (BMP’s) are a family of bone-matrix polypeptides isolated from a variety of mammalian species. Implantation of osteogenic proteins induces a sequence of cellular events that leads to the formation of new bone.

Recombinant human osteogenic protein-1 (rhOP1 or BMP-7) has now been produced and is commercially available.

Rationale: OP.1 has been used in our centre since early 2003 and we now report on our experience with its use in the treatment of fracture non unions in a general orthopaedic trauma setting.

Methodology/Results: OP1 has been used in 19 fracture non unions, the commonest site being the tibia but also in the humerus and forearm. Five of these cases had previous autologous bone grafting. There was one case of deep MRSA infection in a proximal humerus fracture. There were no complications associated with the use of OP1 and specifically there were no instances of symptomatic heterotopic bone formation. Eighteen fractures went on to clinical and radiological union.

Conclusions: Autogenous bone is the current standard in the management of fracture non union because of its high osteogenic potential and biocompatibility. Donor site morbidity and quantity remain drawbacks. The use of OP.1 in the treatment of tibial non unions is well documented in the literature but there is little written about its use in other sites.

We are encouraged by our early experiences with the use of OP1 in numerous anatomical sites and apart from issues of cost would see great potential for further use.

Introduction: The use of allogeneic blood is associated with many complications. A baseline audit performed in our institution in 2000 showed that 11% of patients undergoing primary total knee arthroplasty required post-operative transfusion. Following this audit, patients undergoing primary knee arthroplasty were no longer routinely cross matched, a Haemovigilance Nurse was employed in compliance with the National Blood Users Group guidelines, and post-operative cell salvage was introduced for patients with a pre-operative haemoglobin level of less than 12 g/dL.

Aim: To assess the impact of these changes on our transfusion practice

Methods and materials A prospective audit was performed over a nine month period, from 1^st January to 30^th September 2003. Data was collected on 233 patients who had primary total knee arthroplasty performed during this period. Patients were transfused if their blood loss exceeded a pre-calculated maximal allowable loss, or based on a 48 hour post-operative haemoglobin level.

Results: Seventeen of the 233 patients (7%) received allogeneic blood. The average amount received was two units. Pre-operative anaemia and advanced patient age were predictive for increased risk of transfusion. Thirty six per cent of patients who were given a cell saver did not collect sufficient blood for re-transfusion. Ten per cent of this group required further transfusion with allogeneic blood.

Conclusion: There was no statistically significant difference in either the percentage of patients transfused or the volume of blood given to each patient between the two periods of audit. We did not find post-operative cell salvage to be an effective method of reducing allogeneic blood use.

Sciatic nerve palsy is a recognised complication of primary total hip replacement. In our unit this complication was rare with an incidence of < 0.2% in the past ten years. We describe six cases of sciatic nerve palsy occurring in 355 consecutive primary total hip replacements (incidence 1.69%). Each of these palsies was caused by post-operative haematoma in the region of the sciatic nerve.

Cases, which were recognised early and surgically-evacuated promptly, showed earlier and more complete recovery. Those patients for whom the diagnosis was delayed, and who were therefore managed expectantly, showed little or no recovery. Unexpected pain and significant swelling in the buttock, as well as signs of sciatic nerve irritation, suggest the presence of haematoma in the region of the sciatic nerve.

It is, therefore, of prime importance to be vigilant for the features of a sciatic nerve palsy in the early post-operative period as, when recognised and treated early, the injury to the sciatic nerve may be reversed.

Sciatic Nerve Palsy (SNP) is a recognised complication in Primary Total Hip Replacement after a transtrochanteric or a posterior approach (5). It is considered to be caused by direct trauma to the nerve during surgery. In our unit this complication was rare with an incidence of < 0.2% over the past ten years. However we know describe six cases of sciatic nerve palsy occurring in 355 consecutive primary THRs (incidence 1.60%) performed in our unit from June 2000 to June 2001. Each of these sciatic nerve palsies we believe was due to postoperative haematoma in the region of the sciatic nerve.

To our knowledge there are only five reported cases in the literature of sciatic nerve palsy secondary to postoperative haematoma (1). (Each of the six patients who developed SNP was receiving prophylactic anticoagulation).

Cases recognized early and drained promptly showed earlier and more complete recovery. Those in whom diagnosis was delayed and were therefore managed expectantly showed no or poor recovery. More than usual pain the buttock, significant swelling in the buttock region and sciatic nerve tenderness associated with signs of sciatic nerve irritation may suggest the presence of haematoma in the region of the sciatic nerve. It is therefore of prime importance to be vigilant for the signs and symptoms of sciatic nerve palsy in the early post operative period because if recognized and treated early the potential injury to the sciatic nerve may be reversible.

Neonatal septic arthritis is a true orthopaedic emergency posing significant threat to life and limb.

Objective: To examine the clinical presentation, diagnosis, treatment and outcome of children presenting with septic arthritis in the neonatal period.

Design: Retrospective review of clinical notes and radiographs of children presenting over a 20 year period (1977–97).

Subjects: 34 patients with septic arthritis in a total of 36 joints.

Outcome measures: Clinical outcome was classified as satisfactory or unsatisfactory as per Morrey et al. Radiological outcome was graded I–IV as per Choi et al. Joint instability, destruction, limb length discrepancy and angular deformity were assessed.

Results: The hip joint was affected in 24 of the 34 cases. Pseudoparalysis was the most reliable clinical finding occurring in 29 out of 34 cases. Staph Aureus was isolated as the infecting pathogen in 22/34 patients. Sequelae occurred in 16 hips and 1 knee. Poor prognostic indicators were delayed diagnosis (p< 0.05) and the hip as site of infection (p< 0.01). Clinical outcome was unsatisfactory in 15 patients and satisfactory in 17 patients. Radiological outcome was Choi I or IIA (good) in 12 hips and Choi II to IV in 13 hips (poor). Multiple further reconstructive procedures were required in 15 cases.

Conclusions: Despite optimum treatment, neonatal septic arthritis results in significant long-term morbidity for a high proportion of cases.

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.

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

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

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

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