Prosthetic Joint Infection in Patients with Rheumatoid Arthritis: An Outcome Analysis Compared with Controls

BACKGROUND: Patients with rheumatoid arthritis (RA) have been shown to have an increased susceptibility to the development of prosthetic joint infection (PJI) after hip or knee replacement. However, little information is available on the demographic data, outcome of treatment and prognostic factors in RA patients when compared to those in non-RA patients. METHODS/PRINCIPAL FINDINGS: We performed a retrospective cohort analysis of all cases of PJI that were treated at our institution between 2002 and 2008. Of 346 episodes of PJI during the study period, 46 (13.3%) occurred in patients with RA. Compared to the non-RA cohort, RA patients with PJI were female predominant (74% vs 27%, p<0.001), younger (median age, 51 vs 63 years, p<0.001) and developed infection earlier (median joint age, 72 vs 128 days, p<0.001). The 2-year survival rate free of treatment failure was lower in RA patients with PJI episodes either treated with débridement (22% vs 52%, p = 0.002) or two-stage exchange (78% vs 95%, p = 0.004). A longer duration of symptoms before débridement surgery (median, 11 vs 5 days, p = 0.015), and absence of antibiotics in bone cement for two-stage exchange (relative risk, 8.0; p = 0.02) were associated with treatment failure in patients with RA. DISCUSSION: The outcome of PJI in RA patients was generally worse than that in non-RA patients. Risk of treatment failure increased in the setting of delayed débridement and two-stage exchange without the use of antibiotic-impregnated bone cement. These findings highlight the importance of vigilant monitoring and aggressive treatment for PJI in RA patients.