Risk factors for early wound complications after orthopedic surgery for rheumatoid arthritis.

OBJECTIVE: To identify risk factors for the occurrence of early wound complications following orthopedic surgery in patients with rheumatoid arthritis (RA).
METHODS: We reviewed records of patients with RA undergoing joint surgery to identify predictors of the following early postoperative surgical outcomes: (1) prolonged drainage; (2) wound cellulitis; (3) wound dehiscence; (4) suture abscess; and (5) superficial or deep wound infection.
RESULTS: During the study, 204 patients with RA underwent 119 total knee replacements, 105 total hip replacements and 143 procedures of other joints, for a total of 367 orthopedic surgeries. A total of 57 complications were observed (15.9%) of which 26 were considered major (7%). Of the 230 total arthroplasties of the hip, knee, shoulder or elbow, 3 were followed by early deep wound infections (1.3%). In univariate analysis, factors significantly related to the occurrence of complications included Hispanic ethnicity [relative risk (RR) 1.43, 95% confidence interval (CI) 1.16 to 1.78]. and preoperative use of azathioprine (RR 2.13, 95% CI 1.04 to 4.37). Complications were less frequent among patients given methotrexate, but the differences was not significant. Operative blood loss was inversely related to the occurrence of complications. In the multivariate model, the only significant predictors of complications were Hispanic ethnicity (RR 2.86, 95% CI 1.43 to 5.56) and operative blood loss (RR 0.50/liter lost, 95% CI 0.29 to 0.86).
CONCLUSIONS: We were unable to demonstrate an independent effect of antirheumatic therapy at the time of surgery on the occurrence of postoperative wound complications. Our study suggests that patients with RA of Hispanic ethnicity may be at increased risk of developing postoperative wound complications following orthopedic surgery. Further study is necessary to explain the mechanism of increased complications in this population.