Long-term follow-up of a hydroxyapatite ceramic-coated threaded cup: an analysis of survival and fixation at up to 15 years.

We evaluated the survival of 112 consecutive JRI hydroxyapatite ceramic-coated threaded acetabular components (JRI Ltd, London, UK). Follow-up was for a minimum of 13 years (range, 13-15 years). Patients were assessed clinically and radiographically using the Merle d'Aubigné and Postel scoring systems and the De Lee and Charnley zones. Cup angle, migration, and signs of radiolucency were used to assess loosening. The criteria for failure were revision or impending revision due to pain and septic or aseptic loosening. The mean results of the Merle d'Aubigné and Postel score for pain, motion, and ability to walk were 2.2/2.7/2.2 preoperatively and 5.6/4.3/5.1 postoperatively. There was 100% endosteal bone formation in De Lee and Charnley zones 1 and 3 and 87% in zone 2. No reactive lines were seen in any zone in any cup. There were no cases of migration, change in cup angle, or revision for loosening. Our survival was 99% at 13 years (95% confidence interval, 96-100).