Introduction: Surface replacement of the hip has been proposed as an alternative to total hip replacement, particularly in young active patients. The suggested benefits include preservation of bone stock for future revision surgery and avoidance of proximal femoral stress protection, which can cause bone resorption. However, following femoral head resurfacing, femoral neck fracture can occur.

The aim of this study was to compare the strain pattern in intact and resurfaced femurs using validated third generation composite femurs and rosette strain gauges.

Methods: Rosette strain gauges were applied to an intact and a resurfaced third generation composite femur at three sites; narrowest part of the lateral surface of the neck, narrowest part of the medial surface of the neck and medial surface at the level of lesser trochanter. The femurs were loaded with axial loads of 600N, 800N and 1000N sequentially. The tests were repeated thrice for each femur. Maximum and minimum principal strains were calculated.

Further tests were carried out in which an abductor load was included in the model. Testing was done at 600N and repeated thrice for each femur. The principal strains were calculated and compared with the the principal strains without the abductor load.

Results: The maximum principal strains in the resurfaced femur were approximately 50% higher in the lateral surface of the neck and about 30% higher in the lesser trochanteric region when loaded without including an abductor force. Inclusion of the abductor force decreased the strain particularly at the lateral surface of the neck by approximately 45% in the intact femur and approximately 25% in the implanted femur. Even with the inclusion of the abductor load the strain in the resurfaced femur remained more than 50% higher at the lateral surface of the neck and 20% higher in the lesser trochanteric region.

Conclusion: Our study suggests that proximal femoral stress protection will not occur following surface replacement of the hip. The increased strain at the lateral surface of the neck could result in fracture, particularly if there is notching of the neck or if abductor function has been compromised, which can happen particularly with the direct lateral approach.

Introduction and Aims: Private companies now offer risk assessment packages to hospital trusts. Data is collected using ICD coding and complication rates for individual surgeons are calculated and published. A risk assessment document was recently published at the Royal Gwent Hospital presenting complication rates and misadventures on league tables of specialty and consultants. Serious concerns were raised about the quality of the data.

Method: We undertook a study to independently evaluate the accuracy of data used to calculate these complication rates. Two orthopaedic surgeons with the highest published complication rates were studied. The notes of patients who had suffered complications were retrieved and the published complication data was compared with the clinical interpretation of the actual complication. One hundred and fifty reported complications were analysed.

Results: In most cases data accuracy was woefully inadequate (table 1). For example, revision procedures were counted as complications for the revision surgeon irrespective of who carried out the primary procedure. The normal work up of these patients, including procedures to investigate the presence of infection, are recorded as complications, with some patients being recorded as having up to four separate complications. Misadventures published for surgeons included dural tap during epidural anaesthesia.

Conclusion: The results of this study highlight the potentially devastating consequences of data inaccuracy. Inaccurate published data on complications, used to form league tables for individual surgeons can be career jeopardising. We advocate that consultation with the clinicians involved should always occur before data is published so that these inaccuracies can be picked up and the potentially damning consequences of falsely high complication rates can be avoided.

The use of exhaust suit systems is commonplace in arthroplasty surgery where isolation of the surgical team is desirable in an attempt to reduce the risk of infection transmission. Elevated carbon dioxide levels have been reported in the non-clinical setting with such systems the consequences of which can include fatigue, diapho-resis, nausea, headache and irritability.

The aim of our study was to determine the levels of carbon dioxide present within an exhaust suit system during hip arthroplasty and to compare these with the recommended occupational exposure limit levels published by the Health and Safety Executive (HSE).

Data was collected during ten primary hip replacements performed by the same surgeon whilst wearing the Stryker Steri-Shield Helmet Exhaust System. This is a self-contained unit with an integrated blower used in conjunction with a full-length gown. In addition the helmet was fitted with an air-sampling probe connected to a portable infrared CO2 monitor and also a temperature probe. Thus continuous monitoring of both CO2 and temperature level during surgery was possible.

The mean initial CO2 concentration in the helmet at the beginning of surgery was 3 000 parts per million (ppm) and the mean maximum CO2 level recorded was 13 000 ppm. The mean time the surgeon was within an exhaust suit to perform a primary hip replacement was 1 hr 54 mins and for 86% of this time period the CO2 level within the helmet exceeded the recommended level of 5 000 ppm as stipulated by the HSE.

In conclusion we have demonstrated significantly elevated CO2 levels within the Stryker Steri-shield Exhaust Suit System during hip surgery. Surgeons who use this system should be aware of this together with the physical symptoms that may result.

A previous study done in our unit showed good results in terms of union, stability and function following 2-suture repair of proximal humeral fractures. Healing took place usually with a mild degree of varus angulation but one failure of this technique when the fracture slipped into varus prompted us to re-evaluate our technique. The addition of a third (lateral) suture to the repair has been used as routine following this.

A prospective series of 24 patients with displaced Neer 2 and 3 part proximal humeral fractures was studied. The patients were reviewed at a mean of 22.5 months post fixation. The patients were reviewed clinically and graded according to the Constant Shoulder Score to assess range of movement, power, function and pain. This was compared to the contralateral uninjured shoulder.

Radiographic evaluation of fracture union, avascular necrosis and malunion was performed, and any complications of treatment were noted.

There were 24 2- and 3-part fractures. All the fractures united with no radiological evidence of avascular necrosis. At follow-up there was a mean Constant Score of 71.05 compared with a mean score of 84.5 on the uninjured contralateral shoulder. Active abduction of > 120° was achieved in 9 patients. Intraoperative stability in the varus/valgus plane was noted to be better.

All patients were satisfied with the results; the problem of instability in the coronal plane has not been a problem and the fractures have healed with no varus mal-union. There have been no additional complications with this technique compared to the 2-suture method.

We have successfully achieved stability after open reduction and suture fixation of 2- and 3-oart fractures of the proximal humerus. Following one case of varus instability using a 2 suture technique,

We have routinely supplemented this with a third (lateral) suture. There have been no additional complications using this method, the angulation of the fractures once healed are improved and none of the repairs have had a problem with varus slip.

We set out to determine whether modification of ward facilities and working practices can prevent MRSA infection on an elective Orthopaedic ward, and whether these changes are cost effective.

Following a cluster of 3 cases of acute, deep MRSA infections in arthroplasty patients in early 1999, a review of elective orthopaedic facilities was carried out. The problems identified on the elective Orthopaedic ward were:

inadequate toilet/washing facilities

The following changes were made:

Ward

reduction of beds from 36 to original complement of 30

Staff

regular MRSA screening of all staff

Practices

all patients must have a negative MRSA screen before admission

There has been only one further case of MRSA wound infection in the 1300 major cases that have been through the ward in the last 3 years. This patient spent the first 48 hours post-operatively on the ITU, where MRSA colonisation was widespread.

We performed a cost analysis exercise on the request of our Microbiology department, as they felt that the routine swabbing of so many patients was not cost effective.

We analysed the year 2000 in which 1783 patients were screened for MRSA at a total cost of £24,962 (£14.00 per screen).

A literature search gave us the estimated cost of an MRSA infected arthroplasty being in the order of £31,568, which compares favourably with the total yearly cost of our screening program.

With appropriate facilities and modification of working practices, MRSA infection can be controlled on an elective Orthopaedic ward.

The total yearly cost of our screening programme is less than the potential cost of a single MRSA infected arthroplasty.

The changes made to our working practice and the introduction of our screening programme have been found to be both clinically and cost effective.

The use of exhaust suit systems is commonplace in arthroplasty surgery where isolation of the surgical team is desirable in an attempt to reduce the risk of infection transmission. Elevated carbon dioxide levels have been reported in the non-clinical setting with such systems the consequences of which can include fatigue, diaphoresis, nausea, headache and irritability.

The aim of our study was to determine the levels of carbon dioxide present within an exhaust suit system during hip arthroplasty and to compare these with the recommended occupational exposure limit levels published by the Health and Safety Executive (HSE).

Data was collected during ten primary hip replacements performed by the same surgeon whilst wearing the Stryker Steri-Shield Helmet Exhaust System. This is a self-contained unit with an integrated blower used in conjunction with a full-length gown. In addition the helmet was fitted with an air-sampling probe connected to a portable infrared CO₂ monitor and also a temperature probe. Thus continuous monitoring of both CO₂ and temperature level during surgery was possible.

The mean initial CO₂ concentration in the helmet at the beginning of surgery was 3000 parts per million (ppm) and the mean maximum CO₂ level recorded was 13,000 ppm. The mean time the surgeon was within an exhaust suit to perform a primary hip replacement was 1 hr 54 mins and for 86% of this time period the CO₂ level within the helmet exceeded the recommended level of 5000 ppm as stipulated by the HSE.

In conclusion we have demonstrated significantly elevated CO₂ levels within the Stryker Steri-shield Exhaust Suit System during hip surgery. Surgeons who use this system should be aware of this together with the physical symptoms that may result.

During the last few years there has been renewed interest in hip resurfacing. The advantages of such prostheses include minimal bone resection and more physiological loading of the proximal femur. The purpose of this study was to investigate the stress distribution to the upper femur following a metal-on-metal hip resurfacing and the influence of a short stem on femoral bone loading.

An accurate and validated finite element (FE) model of the proximal femur was utilised. This was created from CT data of cadaveric femurs. The validation process included weighing, modal analysis, strain gauging and ultrasound material testing of the bone. The maximum elastic modulus in the principal direction was 22.9ÊGPa. The elastic moduli of the cement and implant were 1.8 and 200 GPa respectively. The joint force and 4 muscle loads were applied accordingly and adapted to the specific geometry of the bone. The load case represented the 45% position in the gait cycle, corresponding to toe-off. The hip joint force of 2.2kN, approximately 30° superior to the pole of the implant, was applied as a pressure distribution over a 60° spherical segment, modelling the large contact area of the metal-on-metal articulation. Various scenarios with and without an implant were compared.

The distribution of the von Mises stresses in the normal femur without an implant reflected the distribution of the bone’s mechanical properties: the joint load was transferred from the superior surface of the femoral head, through its centre to the dense cortical bone of the calcar and diaphysis. The presence of the resurfacing prosthesis did not significantly affect the stress distribution in the proximal femur, except for a reduction of stresses in the superior region of the femoral head. Varying the length of the stem and its fixation did not significantly affect this stress distribution. A resurfacing prosthesis without a stem resulted in more normal stresses in the superior region of the femoral head.

Compared to the normal femur without an implant the FE analysis of the resurfacing prosthesis demonstrated stress shielding in the superior region of the femoral head. This stress shielding was reduced when a resurfacing component without a stem was used. This advantage must be weighed against the disadvantage that without a stem it is more difficult to accurately position the implant and achieve a uniform cement mantle.

We describe the technique of open reduction and fixation of displaced 2 and 3 part proximal humeral fracture, in which, two ‘figure of 8’ heavy braided sutures are passed through drill holes deep to the bicipital groove and passed through the fracture fragments and the cuff in a tension band fashion.

A series of 12 patients, with a mean age of 65 years (range: 44–75 years), were reviewed at an average of 16 months (range: 4–18 months) after fracture fixation. The patients were assessed clinically, and radiographic evaluation of fracture healing, avascular necrosis and malunion was performed. Any complications of treatment were noted.

All fractures united with no evidence of avascular necrosis. There was some varus deformity in two cases. There was one early loss of reduction but stability was re-established at re-exploration. Good or excellent clinical results were obtained in 10 patients according to the Constant score. Active abduction > 120° was achieved in 75% (nine patients).

Paired suture fixation is an effective means of achieving stabilisation after open reduction of displaced two and three part proximal humeral fractures, with a low rate of non-union while preserving a good functional range of motion. The advantages of this technique are the minimal soft tissue stripping and the avoidance of complications associated with metalwork.

We describe a simple, retroperitoneal approach for the removal of acetabular components that have migrated into the pelvis. The dense fibrous tissue layer which surrounds the implant protects the iliac vessels during removal of the cup by this method.

In 78 consecutive patients, we performed fine-needle aspiration of the hip before revision surgery. At the revision operation biopsies were taken from the capsule and joint tissues. The aspirate and the homogenised soft-tissue specimens were cultured using a radiometric technique. Fifteen hips proved to be infected and 63 sterile on culture of the tissues taken during revision surgery; 94% of the aspiration results were correct. The sensitivity of the technique was 87% and the specificity 95%. Fine-needle aspiration combined with a radiometric culture technique is a simple and reliable method of diagnosing infection of hip prostheses.

A new approach to the hip is described that allows better exposure for difficult revision surgery without the need for trochanteric osteotomy. A V-shaped myofascial flap consisting of the proximal part of vastus lateralis and its fascia with gluteus medius and minimus, is reflected off the greater trochanter and proximal femur giving access to the entire capsule of the hip. If the leg has been significantly lengthened by the revision procedure, abductor tension can be adjusted at closure by altering the reattachment of the flap, analogous to a V-Y-plasty.

Over a 16-year period, 135 custom-made distal femoral prostheses, based on a fully constrained Stanmore-type knee replacement, were used in the treatment of primary malignant or aggressive benign tumours. Survivorship analysis showed a cumulative success rate of 72% at five years and 64% at seven years. Intact prostheses in 91% of the surviving patients gave good or excellent functional results. Deep infection was the major complication, occurring in 6.8% of cases; clinical aseptic loosening occurred in 6.0%. Revision surgery was carried out for loosening and infection, and the early results are encouraging. We conclude that prosthetic replacement of the distal femur can meet the objectives of limb salvage surgery.

The orthopaedic scooter is an alternative to crutches. It gives the patient greater freedom on level smooth surfaces and uses less energy.

Nineteen chondrosarcomas are reported arising in proximal phalanges or metacarpal bones of the hand mainly in elderly patients, predominantly women. The usual clinical presentation was of a progressively painful large tumour, often arising in a dormant lesion near the metacarpo-phalangeal joint. Radiologically most showed some bone expansion with a poorly defined area of destruction and a considerable soft-tissue swelling. Histologically, malignancy was usually obvious, but confusion might arise from the inclusion of bland areas of chondromatous tissue that probably represented the original lesion. Four tumours, initially curetted and grafted, recurred locally and necessitated amputation of the digit or ray. Amputation was the primary treatment for fourteen other tumours and was curative except in one patient who eventually needed amputation through the forearm for a large second recurrence. One tumour was satisfactorily controlled by excision of the affected phalanx. None of these nineteen tumours is known to have metastasised. Correct treatment implies a carefully considered balance between conservation of function and complete removal of all tumour tissue.