Orthopedic Surgery Among Patients With Rheumatoid Arthritis: A Population-Based Study to Identify Risk Factors, Sex Differences, and Time Trends

Objective: To identify risk factors for large-joint surgery (LJS) versus small-joint surgery (SJS) in rheumatoid arthritis (RA) and evaluate trends in surgery rates over time. Methods: A retrospective medical record review of all orthopedic surgeries following first fulfillment of the 1987 American College of Rheumatology criteria for adult-onset RA among residents of Olmsted County, Minnesota between 1980 and 2013 was performed. Risk factors were examined using Cox models adjusted for age, sex, and calendar year of RA incidence. Trends in incidence of joint surgeries were examined using Poisson regression models. Results: A total of 1,077 patients with RA (mean age 56 years, 69% female, 66% seropositive for rheumatoid factor [RF] and anti–cyclic citrullinated peptide [anti-CCP] antibodies) were followed for a median of 10.7 years, during which 112 patients (90 women) underwent at least 1 SJS and 204 (141 women) underwent at least 1 LJS. Risk factors included advanced age, and RF and anti-CCP antibody positivity for both SJS and LJS, and body mass index ≥30 kg/m² for LJS. Risk factors for SJS and LJS at any time during followup included the presence of radiographic erosions, large-joint swelling, and methotrexate use. SJS rates decreased by calendar year of incidence (hazard ratio 0.53, P = 0.001), with significant decline in the rates of SJS after 1995. The cumulative incidence of SJS was higher in women than men (P = 0.008). Conclusion: In recent years, there has been a significant decline in the rates of SJS but not LJS in patients with RA. The incidence of SJS is higher among women. Traditional RA risk factors are strong predictors for SJS and LJS. Increasing age and obesity are predictive of LJS.