OBJECTIVE: The influence of specific medications on the risk of postoperative infection in patients with rheumatoid arthritis and other inflammatory rheumatic diseases (IRDs) remains unclear. This retrospective study examined the risk of postoperative infection at the site of surgery in patients treated with immunosuppressive drugs (including biologic agents) undergoing different types of orthopedic surgery.
METHODS: The study included 50,359 cases of orthopedic surgery performed in our hospital between 2000 and 2008. The primary outcome was operation-related infection. IRD patients were compared with those with degenerative or posttraumatic disorders, and in IRD patients, the effect of immunosuppressive medication, specifically tumor necrosis factor α (TNFα) inhibitors and their preoperative management, was examined.
RESULTS: There were 373 operation-related infections (0.8%) of 47,887 cases in the degenerative/posttraumatic group and 49 (2.0%) of 2,472 in the IRD group (higher infection rate in the IRD group; odds ratio [OR] 2.58 [95% confidence interval (95% CI) 1.91-3.48], P < 0.001). In the IRD group, elbow and foot surgery had the highest infection rates. The risk of infection was significantly increased in patients taking multiple conventional disease-modifying antirheumatic drugs (DMARDs; OR 2.49 [95% CI 1.06-5.84], P = 0.036) or TNFα inhibitors (OR 2.54 [95% CI 1.08-5.97], P = 0.032). The risk was especially high (6 [12%] of 49) if the last dose of TNFα inhibitor was given <1 administration interval before surgery.
CONCLUSION: The risk of postoperative infection was elevated in patients with IRDs, especially those taking >1 conventional DMARD or TNFα inhibitors. It may be advisable to consider stopping TNFα inhibitors ≥1 administration interval before surgery, since the risk of postoperative infection appears to be higher if the operation occurs within this period.