Background There have been various reports on the influence of biologicai agents on surgical site infection and late infection in RA patients, but no concensus has been reached.
Objectives The use of biologic agent has improved rheumatoid arthritis (RA), but orthopedic procedures are still required. There is no consistent evidence for an effect of biologic agents on surgical site infection and late infection. We investigated whether use of biologic agent increased the rate of postoperative infection in patients with RA.
Methods The subjects were 356 RA joints treated with biologics (bio group) and 331 RA joints that were not treated with biologics (control group) at our hospital between January 2006 and December 2011. The mean age of these patients was 59.2 years and the duration of illness was 17.9 years in bio group. The mean age of these patients was 65.1 years and the duration of illness was 16.0 years in control group group.
The biologic used were etanercept (ETN) in 285 joints, infliximab (INF) in 18 joints, tocilizumab (TCZ) in 31 joints, adalimumab (ADA) in 20 joints, and abatacept (ABT) in 2 joints. The surgeries performed were total knee arthroplasty (TKA)(n=121), total hip arthroplasty (THA) (n=42), total elbow arthroplasty (TEA)(n=23), and total ankle arthroplasty (TAA) (n=6) in bio group; and TKA(n=198), THA (n=30), TEA (n=12), TAA (n=5) in control group. The mean duration of drug withdrawal between the final administration of biological agents and surgery was 37.6 days (10-90 days) in cases treated with INF, 17.3 days (8-30 days) in cases treated with ETN, 20.7 days (11-36 days) in cases treated with ADA, and 21.0 days (10-38 days) in cases treated with TCZ and 23.0 days (23days) in cases treated with ABT. The criteria for SSI in the CDC recommendations for prevention of SSI were used in the study. Infectious cases were defined based on diagnosis of a surgical infection by a surgeon. In these cases, antibiotics were administered intravenously or orally. Hematogenous dissemination of infection to the surgical region from infected lesions in distant regions, such as the respiratory organs, urinary tract, and dental caries, more than one year after surgery was regarded as late infection.
Results In the bio group, surperficial infection in 1 joint, deep infection in 3 joints and late infection in 3 joints were found. In the control group, surperficial infection was found in 2 joints and no deep or late infection was detected. Prosthesis removal was performed in patients with deep or late infection. Pathogenic bacteria were commonly MSSA and P. aeruginosa. Infection subsided in all patients and biologics were re-administered with no relapse of infection. The incidence of postoperative infection was significantly higher in cases of foot and ankle joint surgeries compared to that in other surgeries (P<0.001). However, this incidence did not show a significant dependence on use of biological agents. Patients with postoperative infection were significantly older at the time of surgery (65 vs. 62 years old, P<0.001), had a significantly longer duration of rheumatoid arthritis (24 vs. 17.2 years old, P<0.001), and a significantly higher prednisolone dose (3.5 vs. 3.2 mg/day, P<0.001).
Conclusions The key finding in this study was that biological agents did not increase the incidences of SSI and late infection in surgery for patients with RA.
Disclosure of Interest None Declared