Infection and revision rates following primary total knee arthroplasty in patients with rheumatoid arthritis versus osteoarthritis: a meta-analysis

Purpose: This meta-analysis compared infection and revision rates in patients with rheumatoid arthritis (RA) and osteoarthritis (OA) who underwent total knee arthroplasty (TKA). Rates of superficial wound and deep periprosthetic infections were compared in the groups, as were whether revision rates associated with infectious and noninfectious causes differed in the RA and OA groups. Methods: Studies were included in the meta-analysis if they (1) compared infection and revision rates after primary TKA in RA and OA patients; (2) directly compared superficial wound and deep periprosthetic infection rates in RA and OA patients who underwent primary TKA; and (3) reported the actual numbers of RA and OA patients who underwent TKA and developed postoperative infection and/or required revision. Results: The rate of superficial wound infections after primary TKA was similar in the RA and OA groups (15/258 [5.8 %] vs. 77/1609 [4.7 %]; odds ratio [OR] 1.12, 95 % confidence interval [CI] 0.36–3.46; P = n.n.), but the deep infection rate was significantly higher in RA than in OA patients (229/7651 [3.0 %] vs. 642/68628 [0.9 %]; OR 2.04, 95 % CI 1.37–3.05; P < 0.001). The proportion of subjects who required revision resulting from infection after TKA was significantly higher in the RA than in the OA group (86/8201 [1.0 %] vs. 555/118755 [0.5 %]; OR 1.89, 95 % CI 1,34–2.66; P < 0.001), whereas the proportion of subjects requiring revision due to noninfectious causes did not differ significantly (46/594 [7.7 %] vs. 52/904 [5.7 %]; OR 1.22, 95 % CI 0.74–2.00; P = n.n.) Conclusion: Following primary TKA, RA patients had a significantly higher rate of deep periprosthetic infections than OA patients, but their superficial infection rates were similar. The revision rate due to infectious causes was significantly higher in RA than in OA patients, but their revision rates due to noninfectious causes did not differ. Therefore, the surgeon should fully explain to RA patients scheduled to undergo primary TKA that, compared to OA patients, they are more likely to experience a deep infection postsurgery. Level of evidence: Meta-analysis Level III.