The fate of acetabular allografts after bipolar revision arthroplasty of the hip. A radiographic review.

Abstract

We reviewed the radiographs of thirty-one patients (thirty-two hips) who had had revision of the acetabular component of a total hip arthroplasty with a bipolar socket supplemented by allograft and were followed for twenty-four to forty-eight months. The grafts were categorized according to their consistency (solid or crushed bone), the location of the acetabular defect (peripheral [rim] or central), and the extent of the acetabular defect (contained--the medial part of the acetabular wall was intact, or non-contained--it was deficient). We recorded the time to incorporation of the graft, the amount of migration of the socket in the superior and medial axes, and the percentage of graft remaining at the time of the most recent follow-up. The time to healing was similar for all categories of grafts. The central, contained, solid grafts had less resorption than did the central, contained, crushed-bone grafts, as evidenced by less migration of the socket during follow-up. The non-contained grafts, in both peripheral and central locations, were associated with high rates of migration and of instability of the socket.