Short-term results of hydroxyapatite-coated primary total hip arthroplasty.

One hundred consecutive patients who had Howmedica ABG total hip replacements, a system in which the femoral stem and the acetabular component are hydroxyapatite coated, during the period from September 1989 to January 1991 were studied prospectively. Clinical assessment using the d'Aubigné score showed that 96 patients had an excellent score at a minimum of 2 years from the operation. Radiographic analysis, based on DeLee and Charnley criteria for the acetabular cup and on Gruen criteria for the femoral stem, showed equally good results. There was good initial stability of the cup and the metaphyseal portion of the stem, with a secondary increase of load transmission in Zones 2 and 6 with cortical and cancellous thickening.