Modified Pemberton acetabuloplasty for the treatment of congenital hip dysplasia.

Since 1986, the author has been performing a modified Pemberton acetabuloplasty (MPA) with the deliberate aim of producing a greenstick fracture at the sciatic notch. This procedure was performed in 16 girls representing 17 hips. Nine hips (eight patients) were dislocated. Eight hips (eight patients) had residual or primary acetabular dysplasia. In all dislocated hips and in a teratologic sub-luxation, the MPA osteotomy was performed concomitantly with an open reduction and a femoral shortening. All femoral heads remained well covered, with one exception. One hip had a type III avascular necrosis of the femoral head. Two other hips had evidence of premature growth arrest at maturity without previous signs of avascular necrosis. Two hips had arrest of the triradiate cartilage. The contour of the obturator foramen changed in 10 of the 17 hips. This osteotomy is easier to perform than either a Salter or a Pemberton osteotomy. There was no difficulty in obtaining the desired coverage of the femoral head.