Rheumatoid arthritis (RA) is an inflammatory disease that causes the destruction of soft tissues and cartilage around joints. Owing to the widespread use of potent disease-modifying antirheumatic drugs, the need for total knee and hip arthroplasties (TKA and THA) has been reduced in patients with RA. However, the current association between RA and either THA or TKA has not been demonstrated in large-scale epidemiological studies.
We conducted a large-scale retrospective cohort study of patients diagnosed with RA during a 12-year period (2000-2012) in Taiwan. We recruited 32,949 patients with RA and 32,949 individually propensity score-matched non-RA controls.
After adjusting for confounding factors, we found that the risk of THA or TKA was 4.02 times higher in patients with RA than in those without RA (95% confidence interval [CI], 3.77-4.52). The risk of THA or TKA was highest in patients with RA younger than 40 years (adjusted hazard ratio, 43.18; 95% CI, 16.01-116.47). Compared with non-RA patients, patients with RA were 4.82 times more likely to undergo THA (95% CI, 3.84-6.04), 3.85 times more likely to undergo TKA (95% CI, 3.48-4.25), and 19.06 times more likely to undergo both THA and TKA (95% CI, 8.90-40.80).
These findings document a 4.02-fold greater long-term risk of undergoing THA or TKA in RA patients relative to non-RA patients in Taiwan.