Risk of Recurrent Staphylococcus aureus Prosthetic Joint Infection in Rheumatoid Arthritis Patients-A Nationwide Cohort Study

Background. Treatment of rheumatoid arthritis (RA) often involves immune-suppressive therapies. Concern for recurrent prosthetic joint infection (PJI) in RA patients might be high and could reduce use of joint implantation in these patients. We aimed to evaluate the risk of recurrence of PJI in RA patients compared with osteoarthritis (OA) patients by utilizing a large health care system. Methods. We conducted a retrospective cohort study of all patients admitted for a Staphylococcus aureus PJI who underwent debridement, antibiotics, and implant retention (DAIR) or 2-stage exchange (2SE) between 2003 and 2010 at 86 Veterans Affairs Medical Centers. Both RA patients and the comparison group of osteoarthritis (OA) patients were identified using International Classification of Diseases, Ninth Revision, codes. All index PJI and recurrent positive cultures for S. aureus during 2 years of follow-up were validated by manual chart review. A Cox proportional hazards regression model was used to compare the time to recurrent PJI for RA vs OA. Results. In our final cohort of 374 veterans who had either DAIR or 2SE surgery for their index S. aureus PJI, 11.2% had RA (n = 42). The majority of the cohort was male (97.3%), and 223 (59.6%) had a methicillin-susceptible S. aureus PJI. RA patients had a similar risk of failure compared with OA patients, after adjusting for covariates (hazard ratio, 0.81; 95% confidence interval, 0.48-1.37). Conclusions. Prior diagnosis of RA does not increase the risk of recurrent S. aureus PJI. Further studies are needed to evaluate the effect of different RA therapies on outcomes of episodes of PJI.