Function after pelvic tumour resection involving the acetabular ring.

Seven patients subjected to pelvic tumour resection involving the acetabular ring were analyzed with respect to function. In addition to conventional clinical assessment gait was analyzed objectively by means of an electronic walk-way and residual hip-muscle power tested by means of a Cybex II dynamometer. Functional results reported by the patients with respect to pain, walking and working capacity appeared better than those elicited by clinical examination. All patients exhibited a marked pelvic tilt and a positive Trendelenburg sign. Only one patient walked without any kind of support. Leg-length discrepancy was on an average 6 cm. Objective gait analysis disclosed that all patients had reduced weight-bearing time on the operated side as compared to the non-operated. This, however, was clearly less pronounced for those patients who appeared best with respect to pain, walking and working capacity. These patients also showed the best hip extension power which appeared more important from a functional point of view than hip flexion and, surprisingly, hip abduction power. Radiographic examination showed that bony support for the proximal femur, provided either by the formation of a bone shelf from the remaining iliac bone or by the remaining iliac bone itself, was of decisive importance for function. The results of the present study show that pelvic tumour resection involving the acetabular ring, provided radical tumour removal can be achieved, constitutes a feasible alternative to hemipelvectomy from a functional point of view.