To evaluate the clinical and radiographic results of acetabular reconstruction in severe acetabular bony defect using acetabular roof reinforcement ring with hook.

Thirty-five acetabular reconstructions using acetabular roof reinforcement ring with hook were performed between 1993 and 1997 and were followed up for more than two years. Bony defect was classified according to AAOS classification system. The clinical function was evaluated by Harris hip score and radiographical evaluation was focused on the osseous union of the grafted bone, reconstruction of center of rotation and any signs of socket loosening.

The mean Harris hip score improved from 49 points preoperatively to 85 points at the final follow up. The bone graft was incorporated in 33 cases as shown by radiographic remodelling and had a homogenous trabecular appearance. In all cases, the center of rotation was repositioned within three milimeters from the anatomical position. One case was rerevised due to hook failure and postoperative deep infection. Another hook failure without infection was found in one case, but this patient had no radiographic or clinical instability because of bony consolidation after the grafted bone initially settled down at final follow up. Postoperative complications were hip dislocation in 3 hips, nonunion of the greater trochanter in one hip and discomfort at autograft donor site in 3 hips.

Acetabular reconstruction using acetabular roof reinforcement ring with hook combined with morcellised bone graft was considered to be an useful methods especially in severe acetabular bone deficiency.