The aim of this study is to assess the results in total hip arthroplasty with hydroxyapatite (HA) -coated Atoll acetabular cup.

From January 1992 to May 1994, fifty-one primary total hip arthroplasties with HA-coated press-fit Atoll acetabular cup were performed. The patients were followed for an average of 6.2 years (range, 5 to 7.7 years).

The mean Harris hip score increased from 56.1 points preoperatively to 89.9 points at the time of the 5-year follow-up. Serial radiographs revealed a stable bony integration of implants with bone apposition within 1 year. The radiolucent line was noted in 15.7% and was seen initially more than 5 years after surgery. The acetabular component had loosened in 13.7% and the revision rate of acetabular cup was 9.8%. Acetabular osteolysis was seen in 19.6%, mainly at zone 1.

HA-coated Atoll acetabular cup produced initial encouraging results at the bone-implant interface but it could have a risk of bonding loss and mechanical failure.