Risk of medical complications following total hip or knee arthroplasty in patients with rheumatoid arthritis: a nationwide register-based cohort study

Background: Total hip and total knee arthroplasty (THA/TKA) are major surgeries carrying a risk of complications. Patients with rheumatoid arthritis (RA) are at increased risk of venous thromboembolism (VTE), arterial thromboembolic events (ATE), and infections in a non-surgical setting.Objectives: To investigate the risk of VTE, ATE, and non-surgical infection following THA/TKA in patients with RA compared with osteoarthritis (OA); and to explore the impact of biologics treatment.Methods: In a nationwide register-based study, patients with RA and OA who had elective THA/TKA in 2000-2014 were identified in the Danish Hip Arthroplasty Register/Danish Knee Arthroplasty Register and followed up to 90 days after surgery for the occurrence of VTE, ATE, and infections. Cox models stratified on sex and type of surgery (THA vs TKA) and adjusted for age, calendar period, history of chronic obstructive pulmonary disease (COPD), diabetes mellitus (DM), cancer, VTE and CVD were carried out. Outcome information was obtained through linkage with the Danish National Patient Registry.In DANBIO, we identified RA patients treated with biologics within 90 days preceding surgery and estimated their risk of each outcome compared with non-biologics treated RA patients in a Cox model adjusted for the propensity score (PS) of receiving biologics as a restricted cubic spline covariate. The PS was conditional on age, sex, calendar period, use of methotrexate, other csDMARDs, and/or glucocorticoids, pre-surgical DAS28, HAQ-DI, VAS physician, and COPD, DM, cancer and/or VTE.Results: In total, 2899 and 112,571 patients with RA and OA were followed-up (Table). View this table:Table. Patient characteristics and risk of venous thromboembolism (VTE), arterial thromboembolism (ATE), and non-surgical infection following total hip or total knee arthroplasty (THA/TKA) among patients with rheumatoid arthritis (RA) compared with osteoarthritis (OA), and biologics treated compared with non-biologics treated RA patients.Conclusion: In this nationwide cohort study, RA patients were at increased risk of infection after THA/TKA compared to OA patients, but treatment with biologics did not further increase the risk.As seen in other studies RA patients had a lower risk of VTE following TKA when compared with OA patients, but our finding of an increased incidence of VTE in biologics-treated patients warrants further studies.Disclosure of Interests: René Cordtz: None declared, Lars Erik Kristensen Grant/research support from: UCB, Biogen, Janssen Pharmaceuticals, and Novartis, Consultant for: Consultant for AbbVie, Amgen, Biogen, BMS, Celgene, Eli Lilly, Janssen Pharmaceuticals, MSD, Novartis, Pfizer, Roche, Sanofi, and UCB Pharma., Speakers bureau: Pfizer, AbbVie, Amgen, UCB, BMS, Biogen, MSD, Novartis, Eli Lilly and Company, and Janssen Pharmaceuticals, Anders Odgaard: None declared, Søren Overgaard: None declared, Lene Dreyer Consultant for: MSD, UCB and Janssen Pharmaceuticals, Speakers bureau: MSD, UCB and Janssen Pharmaceuticals, Speakers bureau: UCB, MSD, Eli Lilly and Janssen Pharmaceuticals.