Indications and results of intertrochanteric osteotomy in osteonecrosis of the femoral head.

The intertrochanteric osteotomy has been used for several years as a method of treatment of osteonecrosis of the femoral head. As the clinical experience has increased, it has become apparent that, if the procedure is to succeed, specific criteria have to be met. In general, a valgus/flexion osteotomy should be done in patients younger than 40 years who have a Ficat Stage II and/or crescent sign. A necrosis angle of less than 200 degrees as measured on anteroposterior and lateral roentgenograms is also important in predicting a successful outcome. Caudal oblique roentgenograms also help determine the status of the posterior femoral head and whether the osteotomy is feasible. Preoperative planning is important to reduce operating time and obtain a good end result. A 95 degrees blade-plate is used, and if necessary, a small wedge is excised to ensure coaptation of the osteotomy segments. The results of the procedure in 17 patients show that eight patients have a satisfactory result at a mean of three years, while three patients continue to have problems. Five patients have been converted to total hip arthroplasties, and one has a girdlestone arthroplasty. The unsuccessful results occurred in patients who were on corticosteroids or had continued metabolic bone abnormalities. Present experience confirms reports of other series. The operation should be offered only to the small group of patients with idiopathic, posttraumatic, or alcohol-induced osteonecrosis of the femoral head.