The bipolar prosthesis in avascular necrosis of the femoral head

Data are presented from five studies assessing the results of hip joint replacements with bipolar prostheses or total hip arthroplasties. Long-term results of 23 cemented bipolar prostheses were comparable with 14 uncemented bipolar prostheses. Excellent or good results were obtained about 60% of the time. Groin pain was objectionable in at least 12% of the patients. In a study of 43 arthroplasties performed between 1971 and 1982 in 51 patients with systemic lupus erythematosus and avascular necrosis of the femoral head, 29 cemented total hip arthroplasties were compared with 14 bipolar prostheses. Excellent or good results were obtained in 90% of the total hip arthroplasties and only 50% of the bipolar prostheses. A study of the complications and reoperations of both cemented and uncemented bipolar and total hip replacements performed between 1982 and 1986 showed a higher incidence of both complications and reoperations with the bipolar prosthesis. Clearly, the results of bipolar prostheses in avascular necrosis are inferior to those of total hip replacement.