The posterior capsule is variously incised and excised during total hip replacement (THR). There is no consensus on the direction of the capsulotomy and the need to repair the posterior capsule. The objective of this study was to determine the orientation of the collagen fibres and nerves in the posterior hip capsule in patients undergoing THR.

Specimens from five patients with osteoarthrosis of the hip (with no fixed deformity) were obtained and fixed in 10% neutral buffered formalin. Sutures were placed to mark the head and trochanteric end before excising. A standard posterior approach was used. The samples were examined and reported by a pathologist. Samples were processed overnight in a VIP5 automatic tissue processor and embedded in paraffin wax, preserving the location of the suture sites on embedding. Sections were cut at 5 Ïm and routinely stained with haematoxylin and eosin. The van Gieson stain was used for collagen fibres. Nerve fibres were highlighted using immunohistochemistry for S100 protein and blood vessels using an antibody to CD34.

The collagen bundles seen were predominantly parallel to the axis of the specimen. Dispersed within the collagen bundles were small vascular leashes that were parallel with the collagen fibres. The S100 staining revealed that these were neurovascular leashes, with small nerves running alongside the vessels and the collagen. Nerves that separate from the vessels were likely to serve proprioceptive and nociceptive functions.

The direction of the capsulotomy during THR by posterior approach has been traditionally perpendicular to the direction of the capsular fibres. However, if possible, capsulotomy along the orientation of the collagen fibres may be advantageous. As this study demonstrates, it will result in less damage to the capsular collagen fibres, blood vessels and nerves resulting in better capsular repair and healing, and better conservation of pro-prioceptive and nociceptive functions.

Distal humeral fractures are difficult fractures to treat. In the elderly population the problems are compounded by gross comminution and osteoporosis. Concurrent presence of rheumatoid arthritis makes the problem more difficult. Open reduction and internal fixation of such fractures have been shown to give poor results. Total elbow replacement has been recommended as an alternative solution to this difficult problem. We present the results of a retrospective review of a small group of elderly patients who underwent total elbow arthroplasty in our unit for comminuted fractures of the distal end of the humerus.

We have followed up seven patients (seven elbows) with a mean age of 81. 7 years (range 74. 1 to 87. 8) at the time of injury. The presence of rheumatoid arthritis in three of them influenced the choice of treatment. All replacements were performed using the semiconstrained Coonrad-Morrey elbow replacement prosthesis. The duration of follow up at present is between two and four years. None of the patients have been lost to follow up.

At the latest follow up the mean arc of flexion was 20 to 130 degrees. 6 of the patients had no pain while 1 complained of mild pain. All elbows were stable. The Mayo Elbow Performance Score (MEPS) for five elbows was excellent, two scored good. The mean MEPS for all the elbows was 92/100. There were 2 cases of superficial wound infection and no cases of deep infection, ulnar nerve neuritis or component failure.

These results suggest that a semiconstrained total elbow replacement has a role to play in the treatment of carefully selected distal humeral fractures, which cannot be treated by internal fixation due to extensive intraarticular comminution and gross osteopenia. Although these are short-term follow up results they are encouraging outcomes for treatment of one of the most challenging fractures.

A high incidence of complications with wound healing in calcaneum fractures treated with open reduction and internal fixation (25 – 33% of cases) has been reported. In one study 80% of those who had wound complications required surgical treatment of these. Two recent studies have shown that the risk factors for wound complications in this injury are single layered closure, high BMI, extended time between injury and surgery, diabetes, open fractures and smoking. In our unit, out of a small sample of 56 patients undergoing calcaneal fracture fixation, all those who developed wound complications were smokers.

Transcutaneous oximetry is a technique that has been used routinely to assess oxygen perfusion in neonates and also sometimes in peripheral vascular disease (PVD). It has seen greater use as a research tool in PVD and orthopaedic surgery, being used to look at oxygenation around wounds to assess different surgical approaches. This study was performed to assess whether a difference in the oxygen perfusion around the ankle joint could be measured in smokers and non-smokers. A transcutaneous oximetry probe was used to assess the tissue oxygen perfusion at the ankle (posterior to lateral malleolus where the incision line would be) and on the chest (just to the side of the sternum). A standardised technique was used for each patient.

Patients were chosen who had no lower limb orthopaedic problem or known PVD. The groups were matched in terms of sex and average age. The data was analysed after logarithmic transformation using a two-tailed Students t-test. The average pO2 chest/foot ratio was higher in the non-smokers than smokers but this was not significant (p=0.704). The average ankle pO2 was higher in the non-smokers and this was shown to be significant (p=0.026).

Although a small sample, these data suggest that tissue oxygenation around the ankle may be significantly lower in smokers. This would help to explain why they are at increased risk of wound healing complications. This work also demonstrates that transcutaneous oximetry can be a useful tool in orthopaedic research. Tissue oxygenation around other joints could also be assessed in relation to position to discover the optimum position for wound healing.