Significance of subsequent hip unloading after surgical intertrochanteric osteotomy of idiopathic femur head necrosis

PURPOSE: To judge the influence of consequent non-weight-bearing on the postoperative results, we reviewed 28 patients in whom we performed intertrochanteric osteotomies for idiopathic osteonecrosis of the femoral head during the years 1996 and 1997. Postoperatively 12 patients were supplied with a walking device for non-weight-bearing which was used for 1 year. 16 patients were mobilized by using 2 crutches for 15 kp partial weight-bearing until the osteotomy healed up and were then allowed to bear full weight. METHOD: For clinical evaluation of the early results after about 18 month the Merle d'Aubigné hip score was used. Furthermore we analyzed pelvic radiographs for assessing the stage of the necrosis (Ficat staging) and the necrotic angle. RESULTS: Overall 82% good and excellent results were achieved. Due to a longer period of non-weight-bearing the results were again clearly improved (92% versus 75% of patients with partial weight-bearing). It was noticed that there were discrepancies between good clinical results and the less satisfying radiographic findings. CONCLUSIONS: Postoperative non-weight-bearing for about 1 year with the use of a walking device by patients with idiopathic osteonecrosis of the femoral head has clearly a positive effect on clinical results.