Valgus osteotomy for hinge abduction in avascular necrosis.

Femoral head deformity with flattening and lateral protrusion can occur secondary to epiphyseal dysplasia or avascular necrosis of any aetiology in childhood. This deformity causes painful impingement of the lateral femoral head on the acetabular lip, a phenomenon known as hinge abduction. Twenty patients undergoing valgus osteotomy for hinge abduction were clinically and radiologically reviewed. The procedure corrected some leg shortening and improved the abduction range of the affected hip. Overall, 80% of patients did well. Valgus osteotomy is an effective procedure for relieving hinge abduction.