Nonself-centering Bateman bipolar endoprosthesis for nontraumatic osteonecrosis of the femoral head: a 12- to 18-year follow-up study.

We studied the long-term results of bipolar endoprosthetic replacement in 12 patients (12 hips) 12 to 18 years after surgery. These patients had Ficat stage III nontraumatic osteonecrosis of the femoral head. The original Bateman universal proximal femoral endoprosthesis, which did not have a self-centering mechanism, was inserted without cement as a primary surgical intervention. Three patients underwent revision surgery, 3, 17, and 17 years after surgery, respectively. The reasons for revision surgery were migration of the stem in 2 patients and migration of both the stem and the outer cup in 1. In the remaining 9 patients, the total Merle d'Aubigné and Postel score was 16.1 +/-1.3 at the time of follow-up. Radiographs showed migration of the endoprosthesis in 1 of these 9 patients. Thus, 11 of the 12 patients retained the endoprosthesis 12 years or more after implantation. We concluded that the original Bateman endoprosthesis was effective in delaying the need for total hip replacement for more than 10 years in patients with Ficat stage III nontraumatic osteonecrosis of the femoral head.