Transtrochanteric rotational osteotomy of the femoral head for the treatment of osteonecrosis. Follow-up statistics.

Transtrochanteric rotational osteotomy of the femoral head was technically established as a surgical procedure in 1972. This procedure has been successfully performed on 250 hips in 204 patients. In the treatment of idiopathic and steroid-induced osteonecrosis of the femoral head, the results of 128 hips in 90 patients followed two to nine years were reviewed. In 98 of 128 hips, excellent results were obtained clinically and roentgenographically. Progressive collapse in the newly created weight-bearing area occurred in 25 hips where the lesions had been extensive. In 35 of 39 Grade I or II hips, excellent results were obtained in every respect (success rate: 90%). Following the analysis of results on the preoperative lateral roentgenograms of the femoral head, 76 of the 80 hips in the group in which the intact area was greater than one third of the total articular surface showed no collapse of the newly created weight-bearing area, thus accounting for a 95% success rate. In cases when a further collapse was prevented, the necrotic lesions were smaller at follow-up. Excellent results were obtained when the osteotomy was performed during the early stage of necrosis and in the absence of an advanced collapse, even in extensive lesions. In advanced cases with an extensive lesion, adequate anterior rotation is essential and intentional varus position should be designed. These results suggest that this procedure will inhibit progressive collapse of the femoral head and restore the joint more effectively than other surgical procedures.