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.