PERIOSTEAL AUGMENTATION OF THE ACETABULUM

The periosteum in children and especially infants has significant oste ogenic potential, To determine the efficacy of periosteal flaps to ass ist in improving acetabular coverage in children with acetabular dyspl asia, a series of experiments were designed using young rabbits. Three groups of five rabbits each had periosteal flaps fashioned and brough t down from the anterolateral aspect of the innominate bone superior t o the acetabulum and sutured to the capsule of the hip, The study was designed to examine the effects of the periosteal cambium layer in the formation of new bone to augment the acetabulum and to determine the effects of a periosteal flap plus cancellous bone graft. A control gro up of five rabbits underwent a sham operation of an open arthrotomy of the hip. Radiographic and histologic examination at 12 weeks revealed augmentation of the acetabulum with periosteal flaps that resulted in an average improvement of the acetabular index of 3.5 degrees and 6.6 degrees, without and with bone graft, respectively. New bone formatio n from the rim of the acetabulum averaged 3.9 mm with periosteal flaps alone and 4.6 mm with bone graft added. Periosteal augmentation of th e acetabulum in conjunction with established procedures for augmenting acetabular coverage would appear to be a useful procedure for improvi ng coverage of the femoral head in children with acetabular dysplasia.