Double innominate osteotomy.

We performed double innominate osteotomy in twenty-five patients with acetabular insufficiency resulting from congenital dislocation of the hip and other lesions. Following iliac (Salter) osteotomy, the second osteotomy was carried out medial to the obturator foramen in the interval between the symphysis pubis and the pubic tubercle. In children more than six years old, adolescents, and adults, addition of the pubic osteotomy increased the amount of acetabular rotation and coverage of the femoral head that could be achieved. An additional benefit was that the femoral head could be shifted medially, decreasing the length of the femoral lever arm. The improvement in center-edge angle in the twenty-five patients averaged 27 degrees, and the acetabular index decreased an average of 19.5 degrees. The center of the head shifted medially an average of 1.5 centimeters. Hip stability was achieved in twenty-three of the patients.