Survival of Bi-Metric femoral stems in 77 total hip arthroplasties for juvenile chronic arthritis

The survival of 77 cementless total hip arthroplasties using a Bi-Metric femoral stem and two types of acetabular components was analysed in 55 patients with juvenile chronic arthritis. The patients were treated between 1986 and 1996. Their mean age was 8.0 years at the onset of the disease and 28.1 years at the time of surgery. The mean follow-up period was 9.6 years. Follow-up evaluations were conducted 3 months and 1, 4, 8, 12 and 16 years post-operatively. The endpoints of survival analysis were revision surgery, death of the patient or the end of the year 2002. The 10-year survival was 77.6% for the Romanus cup and 49.1% for the TTAP-ST cup. In contrast to these inadequate outcomes, the cementless Bi-Metric stem yielded excellent results with a survival rate of 100% for aseptic loosening during a mean follow-up period of 10 years.