Results of transtrochanteric rotational osteotomy for nontraumatic osteonecrosis of the femoral head.

From 1976 to 1985, transtrochanteric rotational osteotomy was applied to 58 hips of nontraumatic necrosis of the femoral head. Of these, 52 hips were available for the present study. The follow-up periods ranged from one to ten years (average, 5.1 years). Satisfactory results were obtained in 69%, as there was no evidence of progressive collapse of the head. Hips that had had no collapse or slight collapse before osteotomy had a significantly better prognosis, compared with those that had marked collapse of the head. The extent of the lesion as depicted on the preoperative lateral roentgenogram also influenced the eventual function. Patient satisfaction was significantly greater when these lesions were less than 70% (31/37), compared with greater than 70% (5/15).