Mountain biking is increasing in popularity worldwide. The injury patterns associated with elite level and competitive mountain biking are known. This study analysed the incidence, spectrum and risk factors for injuries sustained during recreational mountain biking.

The injury rate was 1.54 injuries per 1000 biker exposures. Males were more commonly injured than females, with those aged 30–39 years at highest risk. The commonest types of injury were wounding, skeletal fracture and musculoskeletal soft tissue injury. Joint dislocations occurred more commonly in older mountain bikers. The limbs were more commonly injured than the axial skeleton. The highest hospital admission rates were observed with head, neck and torso injuries. Protective body armour, clip-in pedals and the use of a full-suspension bicycle confer a significant protective effect.

Purpose: To investigate the mode of presentation, management and outcome of ischaemic contracture following a supracondylar fracture with a pink, pulseless hand.

Methods: We reviewed the database at our tertiary referral unit to identify cases over a 20 year period who had been referred for complications of a supracondylar fracture and/or a Volkmann’s ischaemic contracture.

Results: We identified 20 children with Volkmann’s ischaemic contracture following a supracondylar fracture. Of these, 4 patients (mean age 5, range 2–11) were referred to us with evidence of an ischaemic contracture but they had always had a pink albeit pulseless hand. Two of these 4 had undergone vascular exploration at 48 hours and at 72 hours but despite this developed an ischaemic contracture.

The 2 patients with the most severe contractures have undergone surgical intervention for their contracture, and 2 were managed conservatively with splinting. All 4 cases have residual problems with hand function (mean follow-up 5.5 years, range 2–11).

Conclusions: Volkmann’s ischaemic contracture should be a preventable condition. The pink albeit pulseless hand is at increased risk of ischaemic muscle and nerve damage and should not be ignored as the consequences are potentially devastating.

Significance: Clinicians must consider whether they feel that their management protocols for the pink, pulseless hand are robust and defensible.

Metal-on-metal articulations are increasingly used in THR. Hypersensitivity reactions to the metal ions can occur. The symptoms and signs are similar to a patient presenting with an infected prosthesis. Correct diagnosis before revision surgery is crucial to implant selection and operation planning. We present a practical approach to this diagnostic problem.

The history, clinical findings, hip scores, radiology, serum metal ions, ESR, C-RP, hip arthroscopy and aspirate results, synovial fluid metal ion levels, labelled white cell/colloid scan, 99m-technetium scan, revision hip findings and histology of a typical patient who had an allergic response to a metal-on-metal hip articulation are presented, and how the findings differ from a patient with an infected implant. Clinical examination, hip scores and serum metal ion levels were repeated one year after revision of the metal-on-metal hip articulation to a ceramic-on-ceramic.

In hypersensitivity, the periarticular tissues undergo lymphocyte-dominated infiltration, the histology differs from that found in infection. The white cell labelled/colloid scan also uses this difference for diagnosis. Hip aspiration is the single best investigation for infection.

Conclusion: There is no single investigation available in most hospitals that will reliably differentiate infection from allergy in the painful THR. Hip aspiration, labelled white cell/colloid scan and histology obtained from hip arthroscopy biopsy are the most useful investigations.

Intro: Anatomical abnormality associated with severe developmental dysplasia of the hip presents technical difficulties at THR. Patients often present at a younger age and may have had previous surgery.

We report the difficulties encountered during surgery, and the long term results of patients who had Crowe 3 or 4 DDH and a technically difficult primary hip arthroplasty using the modular S-ROM stem.

Method: 28 patients were entered into the prospective trial. The average age of the patient at surgery was 45 (range 23–74 years). All patients underwent surgery by the senior author using the S-ROM femoral stem. They were followed up for an average of 10 years (range 5–16 years), clinical scores recorded by a clinician other than the surgeon and radiographs were examined by an independent radiologist.

Results: 21 patients required a significant autologous bone graft, one patient had a large allograft and six patients required femoral shortening at the time of their THR.

4 patients had a technical complication during surgery. The average pre-op Harris Hip Score was 37, at 5 years it was 83, and at 10 years 81. The SF12 measure of physical and mental wellbeing was 43.90 physical/54.48 mental at 5 years, and 41.64 physical/54.03 mental at 10 years. The WOMAC average score (the lower the score the better the outcome) was 27 at 5 years and 23 at 10 years.

None of the S-ROM stems had been revised, 2 hips had undergone acetabular revision and one hip had a liner exchange. None of the S-ROM stems were loose at latest follow-up. Four hips had osteolysis in Gruen zone 1, one hip had osteolysis in zone 7, and one hip had osteolysis in zone 1 and 7. There was no evidence of osteolysis around or distal to the sleeve.

Conclusion: The S-ROM stem used in primary THR shows excellent results at 10 years in patients with anatomical abnormality related to severe DDH.

S-ROM stem/sleeve modularity allows femoral component anteversion independent of the position of best fit in the proximal femur, and helps overcome the technical difficulty in these patients.

Bone allograft use in trauma and orthopaedic surgery is limited by the potential for cross infection due to inadequate acceptable decontamination methods. Current methods for allograft decontamination either put the recipient at risk of potentially pathogenic organisms or markedly reduce the mechanical strength and biological properties of bone. This study developed a technique of sterilization of donor bone which also maintains its mechanical properties.

Whole mature rat femurs were studied, as analogous to strut allograft. Bones were inoculated by vortexing in a solution of pathogens likely to cause cross infection in the human bone graft situation. Inoculated bones were subjected to supercritical carbon dioxide at 250 bar pressure at 35 degrees celsius for different experimental time periods until a set of conditions for sterilization was achieved. Decontamination was assessed by vortexing the treated bone in culture broth and plating this on suitable culture medium for 24 hours. The broth was also subcultured. Controls were untreated-, gamma irradiated- and dehydrated bone. Mechanical testing of the bones by precision three-point bending to failure was performed and the dimensions and cross-section digitally assessed so values could be expressed in terms of stress.

Mechanical testing revealed bone treated with supercritical carbon dioxide was consistently significantly stronger than that subjected to gamma irradiation and bones having no treatment (due to the minor dehydrating effect of the carbon dioxide). Terminal sterilization of bone is achieved using supercritical carbon dioxide and this method maintains the mechanical properties.

The new technique greatly enhances potential for bone allograft in orthopaedic surgery.

Intro: Total knee replacement (TKR) manufacturers offer the option of high flexion tibial tray inserts. The polyethylene is narrower posteriorly than the standard insert and comes with the theoretical risk of reduced longevity due to thinner implant. This trial studied both the intra-operative and post-operative difference in knee flexion.

Method: 100 consecutive patients undergoing posterior stabilized Genesis II TKR with Brainlab navigation were studied. The flexion of each knee was assessed per-operatively using the Brainlab navigation system for both the high flex and standard tibial insert trials. Patients were then randomized to receive either a high flex or standard definitive implant and the knee flexion measured clinically with a goniometer six months post op.

Results: Intra-operatively the high flexion insert trial flexed more than the standard flex option by 3.2 degrees. Clinically at six months post op there was no difference in knee flexion between the two groups.

Conclusion: There is no clinical difference in knee flex-ion at six months post-op in patients with a high flex or standard tibial insert. However, we believe that in certain technical circumstances the high flex option is a valuable option for the surgeon to have available.

Objective To survey current antithrombotic prophylaxis regimes of foot and ankle surgeons in the UK, and their self-reported rates of deep vein thrombosis (DVT) and pulmonary embolism (PE).

Method A postal questionnaire was sent to 180 members of the British Orthopaedic Foot and Ankle Society requesting regime and types of antithrombotic prophylaxis (if any) used for elective forefoot, elective midfoot, open elective ankle, elective ankle arthroscopy and ankle trauma surgery, and numbers of cases of DVT and PE.

Results Ninety surgeons responded (50%). Surgeons had been practising as consultants with a special interest in foot and ankle surgery for an average of 8.9 years, and performed an average of 24 foot and ankle cases per month. Ten per cent never used antithrombotic prophylaxis in foot and ankle surgery, 64/90 used it routinely for certain cases, and 17/90 used it routinely in all patients. The most common types of prophylaxis were low molecular weight heparin, aspirin and TED stockings. In an approximate overall total of 223,500 foot and ankle cases, the self reported DVT rate was 0.1%. There were 45 reported PEs (0.02%). There was no significant difference in the rate of DVT between those who never, sometimes or always used prophylaxis. Only 5.5% surgeons employed a specific screening protocol to identify high risk patients.

Discussion There is widely varying clinical antithrombotic practice among foot and ankle surgeons in the UK, with no significant difference in reported DVT rates. This has implications for clinical practice and medicolegal issues.

Aims: To assess the impact of ring fencing of elective orthopaedic arthroplasty patients on rates of post-operative infections including methicillin resistant staphlococ-cous aureus (MRSA). Method: For one year the rate of all postoperative infections in patients undergoing hip or knee arthroplasty were recorded (including chest, urinary, wound etc). Patients were treated using standard precautions against infection employed in most modern orthopaedic units. The elective ward was then ring fenced; admitting only elective patients who had clear swabs for infection taken in the community. Patients of other specialities and trauma were excluded. In addition barrier nursing and infection control measures were employed. The infection rate was then recorded for one year. Results: Prior to ring fencing there were 43 post-op infections in 417 patients (9 MRSA). In the ring fenced patients there were 15 infections in 488 patients (no MRSA). Conclusions: Ring fencing elective orthopaedic beds reduced overall infection rate, eradicated MRSA and allowed 17% more joint replacements to be performed. We recommend these precautions in all orthopaedic centres.

For one year (July 1999-July 2000), the rate of post-operative infection in patients undergoing joint arthroplasty was recorded (including wound, chest UTI etc). Standard precautions against infection used in most orthopaedic units in the UK were employed.

In July 2000 elective orthopaedic beds were ‘ring-fenced’. Only elective orthopaedic patients who had negative swabs for MRSA in the community were admitted. Eradication therapy was commenced in the community if appropriate. Trauma and other specialties’ patients were excluded.

In addition to standard precautions, nurses wore a disposable apron and gloves for each intervention. Antibacterial hand cleanser was installed by each bed, and staff expected to use it after each consultation. Doctors left jackets at the door and donned clean white coats for ward rounds. These were left on the ward and laundered daily. New cleaning regimes were adopted.

Pre ring-fencing, 417 joint replacements were performed and 60 patients were cancelled due to no bed. There were 43 post-op infections, 9 of which were MRSA. In the year post ring-fencing, 488 joint replacements were performed; there were no cancellations due to bed shortage. There were 15 post-op infections and no MRSA.

Eight patients swabbed positive for MRSA in the community, and were admitted after eradication therapy with no infections post-op.

We concluded that ‘ring-fencing’ of elective orthopaedic beds reduced cancellations, reduced the overall infection rate and abolished MRSA.

We have continued to ring-fence elective beds following this study, and recommend these precautions be employed in all units dealing with elective orthopaedic patients.

Many methods have been described over the past 5 years for repair of articular cartilage defects. The best reported results have been from the use of autologous chondrocyte transplantation (ACT)(1) and mosaicplasty.(2) There have, however, been no prospective clinical trials of these two methods. In this trial 70 patients were prospectively randomized to receive either autologous chondrocyte transplantation (37) or mosaicplasty (33) in the knee. 37 patients were female and 33 male. The average age was 32 years (16 – 44). The indications for surgery were persistent pain and mechanical symptoms in the knee with an isolated defect of the articular cartilage. 38 (56%) were post-traumatic, 12 (16%) due to osteochondritis dissecans, 10 (14%) due to previous meniscectomy, and 10 (14%) due to chondromalacia patellae. The size of the defects ranged from 2cm2 to 12cm2 (mean 4.8cm2). There were 35 defects on the medial femoral condyle, 13 on the lateral femoral condyle, 17 on the patella and 5 on the trochlear. 31 patients were undergoing primary surgery and 39 secondary surgery. All were independently reviewed using the Visual Analogue Pain Score, the Cincinatti Pain Score and the Stanmore Score. Patients were arthroscoped at one year with MRI scan and biopsies where possible.

Results: The visual analogue pain score improved overall from a mean of 5.4 (range 3.4 – 7.4) pre-operatively to 3.9 (1.8 – 5.1) at one year review. Similarly the Cincinatti pain score improved from 6.5 pre-operatively to 10.2 post-operatively and the Cincinatti function score improved from 46 to 62 at one year before sport commenced. Overall 71% (49) patients were excellent or good on the clinical scoring scales, 15% (11) were fair, and 14% (10) were poor. The 10 poor results were no different from the main group with regard to age, sex, pain level or site or size of lesion. However, 5 were secondary procedures, 2 had multiple lesions, and 3 had had previous ruptured anterior cruciate ligaments. Arthroscopy and biopsy of 21 lesions so far after one year has shown mature articular cartilage in 2, and immature cartilage in 19. In all cases there was bonding of the repair tissue to the underlying bone. This study is already clarifying the role of ACT and mosaicplasty in the management of cartilage defects in the knee and also the necessity for the use of periosteal covering membrane.

This study examined the reliability of pre-operative templating of the femur in total hip replacement (THR), and the accuracy of the templates provided by leading arthroplasty manufacturers. Templates are provided by arthroplasty manufacturers to be used with pre-operative radiographs as an aid to selecting the appropriate size of prosthesis that will allow an optimal cement mantle in THR. These templates vary in magnification from 10-20% (Mode 15%).

A retrospective review of the pre- and post-operative AP pelvis radiographs of 50 randomly selected patients who underwent THR in 1998 was performed. The radiographs were taken using the uniform standard technique. The magnification of the post-op radiograph was calculated by measuring the femoral head size. This was compared to the magnification of the pre-op radiographs using the ratio of the inter-teardrop distance. The post-operative radiographs were templated using a 15% template and compared to the size of prosthesis inserted.

The mean radiograph magnification was 22.5% (range 10.7 to 32.6%), with the majority (74%) between 20–25%. The 15% template oversized the prosthesis in 68% of cases. A 10% template would have been inaccurate in 96% of our sample group.

In a standard AP pelvis radiograph, the only variable that affects magnification is the extent to which the patient’s soft tissues raise the bony structures away from the plate. This variation in magnification renders preoperative templating of the femur in THR unreliable. Accuracy could be improved by using templates with a magnification of 22.5%.