Intertrochanteric osteotomy for osteonecrosis.

Intertrochanteric osteotomy is an effective surgical option in certain well-selected cases of osteonecrosis of the femoral head. The size of the lesion on plain radiographs in the anteroposterior and lateral projections is a critical determinant of success. The best candidates are patients with less than 50% of head involved in the necrotic sector. Collapse of the femoral head is not a contraindication to osteotomy. Location of the necrotic sector determines whether varus, valgus, flexion, or extension are most appropriate alone or in combination.