The bipolar endoprosthesis and bone graft in the management of aseptic acetabular component loosening

Ten patients with large acetabular defects underwent hip arthroplasty revision with the use of allografts in conjunction with a bipolar prosthesis. Six patients had solid femoral head allografts and the others, morselized allografts. Radiographs at 2-year follow up showed an average of 8 mm of superior migration and 4 mm of medial migration. Our experience has shown that bipolar revision arthroplasties tend to migrate against the allograft. We recommend that bipolar revisions be limited to small acetabular defects that give the bipolar prosthesis full rim contact.