Curved intertrochanteric varus osteotomy for osteonecrosis of the femoral head.

We reviewed the outcome of curved intertrochanteric varus osteotomy in the treatment of osteonecrosis of the femoral head in 20 hips. A mean varus angulation of 31 degrees was obtained by the osteotomy. The ratio of intact area on the weight-bearing portion increased from 19% to 61%. The mean elevation and lateral displacement of the greater trochanter were 1.2 cm and 0.5 cm, respectively. These changes in the position of the greater trochanter were very small when compared with those after conventional varus wedge osteotomy. Nonunion or delayed union was not observed. Quantitative analyses showed aggressive bone remodelling in the medial intertrochanteric region. Eighteen hips survived without collapse after a mean follow-up of 48 months. We conclude that curved varus osteotomy can be used to preserve the hip joint in patients with osteonecrosis of the femoral head.