We report on minimum 10-year follow-up results of total hip arthroplasties with hydroxyapatite (HA)-coated cementless acetabular cups.

From January 1992 to October 1994, we performed one-hundred eight primary total hip replacements in ninety-seven patients using HA-coated cementless acetabular cup. Eighty-four cases in seventy-seven patients were followed-up for a minimum of 10 years.

The mean Harris score was 54.7 (range, 0 to 77.2) points preoperatively and 88.5 (range, 27.1 to 100) points at the most recent follow-up. Revision procedures were required on twenty-eight (33.3%) hips. Thirteen (15.5%) cups were revised because of loosening. Seven (9.5%) hips among the eight that revealed excessive polyethylene wear and osteolysis were revised and one hip is waiting for the revision procedure. In seven (8.3%) cases, only a polyethylene liner exchange was performed because of excessive liner wear without osteolysis. The mean linear polyethylene wear was 2.74 mm. The mean linear wear rate was 0.28 mm per year and the corresponding estimate of volumetric wear was 1689.15 mm³. The mean linear polyethylene wear and linear wear rate in revised hips was 3.05 mm and 0.33 mm per year, respectively. The estimated volumetric wear in the revised group was 1882.27 mm³.

HA-coated cementless acetabular cup (Atoll®) demonstrated a high rate of loosening and poor results in wear and osteolysis. Further studies are needed to promote the design of acetabular cups and the technique of HA coating.