Similar performance with electrochemically deposited hydroxyapatite coating versus plasma porous spray in press-fit acetabular components for primary total hip arthroplasty: a randomised controlled study of early outcomes with DEXA

BACKGROUND: Hydroxyapatite (HA) is an osteo-inductive material commonly added to the surface of components to enhance bone implant fixation; however, clinical studies have demonstrated inferior performance of HA coated acetabular cups in total hip arthroplasty. This study aims to compare the performance of a contemporary acetabular cup either with or without electrochemically deposited HA. METHODS: 50 patients were randomised to receive an acetabular cup either with plasma porous spray (PPS) or an electrochemically deposited HA coating during primary THA for osteoarthritis. Acetabular bone remodelling behaviour adjacent to the cup was assessed using dual energy x-ray absorptiometry (DEXA) scans by a blinded observer at 6 weeks, 3, 6 and 12 months. Patient-reported outcomes and satisfaction were recorded at the same time points. RESULTS: No significant differences in periacetabular BMD changes over time between the 2 different cup types was observed. Both cohorts showed significant improvement in PROMs over 12 months postoperatively with no significant difference in satisfaction. There were no revisions or component loosening in either group up to 12 months. CONCLUSIONS: This study found similar clinical performance and acetabular BMD changes for both porous plasma and electrochemically deposited HA coated cups in primary THA up to 12 months postoperatively.