THE FULLY HYDROXYAPATITE-COATED TOTAL HIP IMPLANT - CLINICAL AND ROENTGENOGRAPHIC RESULTS

The clinical and roentgenographic results of 54 fully hydroxyapatite ( HA)-coated primary total hip arthroplasties in 45 patients was studied . Both the femoral and the acetabular components had a 200-mu m coatin g of hydroxyapatite. The mean age of the patients was 54.8 years. Twen ty-three patients were between 45 and 60 years of age. There were 24 m en and 21 women. Nine patients under went bilateral operations. The av erage follow-up period was 46.9 months (range, 24-78 months). The aver age preoperative Harris hip score was 48, and the average postoperativ e Harris hip score was 94 at 1 year and 96 at 2 years. Revision surger y for component loosening and infection was carried out in four (7.4%) cases. There was aseptic loosening of the femoral component in one ca se (1.85%) and of the acetabular component in two cases (3.7%). Roentg enographic evaluation indicated that greater stress transfer occurs in tile distal two thirds of the femoral stem. Proximomedial femoral nec k resorption was noted in 23 cases (57.4%). Excellent to good clinical outcome was obtained in 89% of patients. in the short term, the rate of aseptic loosening of the fully HA-coated hip prosthesis in our seri es is higher than the reported rates of aseptic loosening of proximall y HA-coated total hip implants. Controlled clinical studies would be r equired to evaluate the relative efficacy of the fully HA-coated and t he proximally HA-coated hip prostheses.