Acetabular reconstruction using bipolar endoprosthesis and bone grafting in patients with severe bone deficiency

Eighty-one patients who had hip reconstruction with bone grafting and bipolar endoprosthesis for severe acetabular deficiency were reviewed retrospectively at 3 to 8 years postoperatively. Failed total hip arthroplasty was the most common indication for operation. Bone grafts were fixed bone blocks, morselized cancellous bone, and wafer-type grafts used singly or in combination. The average Harris hip rating score was 49.9 points preoperatively, 81.4 points at 1 year, and 70.8 points at latest followup examination. The 35 unsuccessful procedures included 25 reoperations for implant removal (resection arthroplasty or revision) and 10 cases pending revision. At latest followup examination, 54.7% of patients considered themselves improved and 62.7% had no or mild pain. Eighty-five percent of cases had radiographic evidence of component migration that was superior and medial in direction. Overall probability of implant survival was 96% at 1 year, but only 47% at 6.5 years postoperatively. Because of the high failure rate, this procedure has a limited role in hip reconstruction, but may be a reasonable part of a staged reconstruction for patients with massive bone loss or in certain revision cases where instability is a concern.