Patient-Reported Outcome Measures After Direct Anterior Total Hip Arthroplasty Are Comparable Between Patients With Rheumatoid Arthritis and Osteoarthritis: A Propensity-Matched Analysis.

INTRODUCTION

It is currently unclear whether patients with rheumatoid arthritis have similar functional outcomes after total hip arthroplasty (THA) as those with osteoarthritis, particularly given that rheumatoid arthritis may have systemic manifestations in terms of pain and function. The purpose of this study was to compare patient-reported outcome measures between patients with rheumatoid arthritis and matched control patients with osteoarthritis who underwent direct anterior THA.

METHODS

All patients who underwent direct anterior THA from 2010 to 2022 at a single academic institution were retrospectively reviewed. Hips with rheumatoid arthritis were propensity matched to hips with osteoarthritis on a 1:4 basis. Patient-reported outcome measures, including visual analog scale (VAS) pain at rest and with use, Hip Disability and Osteoarthritis Outcome Score Pain, and Forgotten Joint Score-12, were obtained at follow-up. In addition, modified Harris Hip Scores (mHHS) were obtained both preoperatively and at the final follow-up.

RESULTS

Forty-six hips with rheumatoid arthritis and 184 hips with osteoarthritis were followed for a mean of 6.3 ± 3.6 years. Both cohorts demonstrated notable preoperative to postoperative improvements in mHHS ( P < 0.001). No differences were observed at the final follow-up between cohorts for VAS at rest (0.8 vs. 0.5, P = 0.333), VAS with use (1.3 vs. 0.9, P = 0.234), Hip Disability and Osteoarthritis Outcome Score Pain (90.4 vs. 93.6, P = 0.113), Forgotten Joint Score-12 (80.3 vs. 82.8, P = 0.529), and mHHS (86.9 vs. 89.0, P = 0.335). One patient with rheumatoid arthritis had an intraoperative periprosthetic calcar fracture, whereas none underwent subsequent revision THA.

CONCLUSION

Patients with rheumatoid arthritis and osteoarthritis who underwent direct anterior THA achieved comparable outcomes in this propensity-matched analysis. Although patients with rheumatoid arthritis may be at an increased risk of complications and revision surgery, patients can expect reduced pain and improved functional outcomes similar to those with osteoarthritis following primary THA.