Aseptic loosening of 2 rim-fix, hydroxyapatite-coated acetabular cups.

Two cases of aseptic loosening in the 11th and 12th year of follow-up of the same acetabular component of a fully hydroxyapatite (HA)-coated total hip arthroplasty are presented. The acetabular cup was a rim-fix type, HA-coated, titanium hemispherical shell secured to the bony acetabulum with titanium screws at the peripheral polyethylene rim. The short-term and midterm results were good with HA-coated total hip arthroplasties, but further studies are needed to investigate whether the >10-year survival of these cups is as good as the survival of cemented ones.