In 12 patients, we measured the oxygen concentration in the femoral head-neck junction during hip resurfacing through the anterolateral approach. This was compared with previous measurements made for the posterior approach. For the anterolateral approach, the oxygen concentration was found to be highly dependent upon the position of the leg, which was adjusted during surgery to provide exposure to the acetabulum and femoral head. Gross external rotation of the hip gave a significant decrease in oxygenation of the femoral head. Straightening the limb led to recovery in oxygen concentration, indicating that the blood supply was maintained. The oxygen concentration at the end of the procedure was not significantly different from that at the start.

The anterolateral approach appears to produce less disruption to the blood flow in the femoral head-neck junction than the posterior approach for patients undergoing hip resurfacing. This may be reflected subsequently in a lower incidence of fracture of the femoral neck and avascular necrosis.

The aim of operative treatment for ankle fractures is to allow early movement after internal fixation. The hypothesis of this study was that early mobilisation facilitated by a removable cast after internal fixation of ankle fractures would improve functional recovery of patients compared with that after conventional immobilisation in a cast.

Sixty-two patients between the age of seventeen and sixty-five with ankle fractures that required operative treatment were randomly allocated to two groups: immobilisation in a non weight bearing below knee cast for six weeks or early movement in a removable cast (at two weeks after removal of sutures) for the following four weeks. The follow-up examinations which consisted of subjective (clinical, Olerud-Molander score, AOFAS score, SF 36) and objective (swelling measurement, x-ray) evaluations were performed at two, six, nine, twelve and twenty four weeks post-operatively. Time of return to work was recorded.

There were two post-operative complications in the group treated with immobilisation in cast; two patients had deep vein thrombosis (DVT). There was one superficial wound infection treated with oral antibiotics and two deep wound infections requiring removal of metal in the group treated with early movement in a removable cast. Patients in group two (early movement) had higher functional scores at nine and twelve weeks follow-up. They also returned to work earlier (63.7 days) compared with the ones treated in cast (94.9 days). There was no statistical difference in Quality of Life (SF-36 Questionnaire) at six months between the two groups.

Early movement with the use of removable cast after removal of sutures in operated ankle fractures decreases swelling, prevents calf muscle wasting, improves functional outcome and facilitates early return to work of patients. Our findings support the use of a removable cast and early exercises in selected, compliant patients after surgery of the ankle.