Five- to Fifteen-Year Clinical Results and the Radiographic Evaluation of Acetabular Changes After Bipolar Hip Arthroplasty for Femoral Head Osteonecrosis

We have studied 36 hips in 30 patients with osteonecrosis of the femoral head who were treated with bipolar hip arthroplasty. Follow-up period was 5 to 15 (average 7.7) years. Five hips were revised. Hips were divided into 2 groups. Sixteen hips with Ficat stage II or III osteonecrosis were assigned into group I, and 15 hips with Ficat stage IV osteonecrosis were assigned into group II. There was no statistical difference between the clinical results of the 2 groups (P = .74). Radiographically, there was minimal migration in group I. There was a statistical significance in superior migration between subgroups with and without osteolysis in group II (P < .01). We emphasize that bipolar hip arthroplasty is indicated for Ficat stage II or III in osteonecrosis of the femoral head.