Introduction

Cementless acetabular fixation in total hip replacement (THA) is reliable and has been the fixation method of choice in the United States for decades. While revision for failure of osseointegration or early loosening is relatively rare, recurrent dislocation remains a leading cause of early revision. Novel acetabular implants and those offered by smaller companies often lack constrained or dual mobility liners, which may result in revision of well-fixed, well-positioned cups in cases of recurrent dislocation.

The purpose of this study was to compare outcomes of THA with three different acetabular cups with differing fixation surfaces. One hydroxyapatite (HA)-coated cup (Trident, Stryker, Kalamazoo, MI, USA) offered dual mobility or constrained liner options. The other cups were a novel highly porous cup (Restoris PST, Stryker, Kalamazoo, MI, USA), and a Calcium Phosphate (CaP)-coated cup (Trinity, Corin, Cirincester, UK), neither of which offered dual mobility or constrained options at the time of investigation. Endpoints of interest were: clinical and radiographic outcomes including evidence of osseointegration, overall reoperations, reoperations for acetabular fixation failure, and reoperations to address dislocation in which a well-positioned shell was revised due to the lack of dual mobility or constrained options.