Incidence of infectious complications in hip and knee arthroplasties in rheumatoid arthritis and osteoarthritis patients.

INTRODUCTION Rheumatoid arthritis (RA) is one of the major indications of total hip (THA) or knee (TKA) arthroplasty. International studies have suggested that RA is a risk factor for prosthesis infections. OBJECTIVES To compare patients with RA and patients with osteoarthritis (OA) of other etiologies with regard to the incidence of prosthesis, incisional, and other systemic postoperative infections in THA and TKA. METHODS Retrospective, comparative cohort of patients followed up after undergoing THA or TKA at the Hospital SARAH-Brasília, from 1996 to 2007. RESULTS Seventy-five arthroplasties (28 TKA and 47 THA) were identified in RA patients. As controls, 131 surgeries (56 TKA and 75 THA) in OA patients were randomly selected and stratified by surgery and gender. No significant difference was observed between the RA and OA groups regarding the rates of prosthesis infections (TKA 7.1% vs. 0% and THA 2.1% vs. 0%, respectively, both with P > 0.1), incisional infections (TKA 14.3% vs. 3.3% and THA 4.3 vs. 1.3%, respectively, both with P > 0.1), and systemic infections (TKA 7.1% vs. 3.6%, P = 0.92 and THA 4.3% vs. 10.7%, P > 0.1, respectively). After multiple logistic regression, the results did not change. CONCLUSIONS RA was not identified as a risk factor for perioperative infections in THA and TKA in this case series of the Hospital SARAH-Brasília, as compared with the group of patients with primary OA or OA secondary to non-inflammatory diseases. The low incidence of infections in both groups may explain our findings.