Revision Risk Following Total Hip Arthroplasty in Patients With Rheumatoid Arthritis: A Cohort Study From the Australian Orthopaedic Association National Joint Replacement Registry

ABSTRACT Background Total hip arthroplasty (THA) is one of the most successful orthopaedic procedures and provides good functional outcomes in both rheumatoid arthritis (RA) and osteoarthritis (OA) patients. However, RA patients face higher risks of adverse post‐operative outcomes. Despite recognising the unique risks of RA autoimmunity and drug therapy, there remains minimal RA‐specific evidence to guide arthroplasty surgeons. Methods This study analysed the rate of all cause revision, and revision for infection, dislocation, periprosthetic fracture, and aseptic loosening for 3657 RA and 446 428 OA patients who underwent primary THA recorded in the Australian Orthopaedic National Joint Replacement Registry (AOANJRR). Results Key findings of this study indicate that RA is associated with a younger age at THA, an increased risk of all‐cause revision (HR 1.35; 95% CI 1.16–1.56; p = 0.001), and an increased risk of revision for infection (HR 1.48; 95% CI 1.12–1.98; p = 0.006), dislocation (HR 1.87; 95% CI 1.45–2.42; p < 0.001), and early aseptic loosening (0–3 month; HR 2.81; 95% CI 1.50–5.26; p = 0.001). There was no difference in all‐cause revision for cemented, cementless, or hybrid THA fixation in RA patients. Conclusion This study suggests that RA continues to be associated with worse post‐THA outcomes compared to OA. Further research is needed to develop strategies that improve perioperative management of inflammation and immune suppression to reduce the risk of post‐operative complications in RA patients undergoing THA.