Transtrochanteric posterior rotational osteotomy for osteonecrosis.

When osteonecrosis is located in the mid- to posterior region, we generally perform a transtrochanteric posterior rotational osteotomy. We retrospectively reviewed the clinical and radiographic results in 47 consecutive patients (51 hips) in whom we performed posterior rotational osteotomies. The average age was 37 years at the time of surgery. There were 30 male and 17 female patients. Thirty-six hips were ARCO Stage III, and 15 were Stage IV. Conversion to THA was defined as the failure end point. Three patients died and one was lost to followup. We were therefore able to follow 43 patients (46 of the 51 hips, or 90%) a minimum of 1.2 years (average, 12 years; range, 1.2-21 years). We used the Harris hip score for preoperative and most recent followup. The average preoperative Harris hip score of 52 points improved to an average of 84 at the latest followup. Radiographically, the osteonecrosis in 30 hips (65%) had no progressive collapse, and 13 (28%) showed osteoarthritic changes, but no patients underwent THA. A posterior rotational osteotomy appears useful for patients with extensive necrosis and advanced collapse.