Session: Poster Session: Prosthetic Joint Infections
Saturday, October 25, 2008: 12:00 AM
Room: Hall C
Background: Infection is a severe complication of TJA. Its Incidence is increased in pts with TNF blockers. To assess the natural history and risk factors of TJA infection in pts receiving TNF blockers, through a national register and a case-control study. Methods: Cases of TJA infections were collected through a national register (RATIO) over 2 years. Two matched controls per case (age, underlying disease) with TNF blockers and TJA, but without infection, recruited in a tertiary care center. All cases were validated by ID specialists. Results: 20 cases (mean age: 57.3 yrs, M/F ratio: 1/19, 18 rheumatoid arthritis)received etarnercept (5), infliximab (7), adalimumab (8). TJA infections involved knee (60%), hip (20%), shoulder (10%), ankle (5%). Causative bacteria were Staphylococcus (75%)( S. aureus (65%)), Streptococcus (20%), Enterococcus (5%), E. coli (5%), 2 infections were bimicrobial. 20% were admitted in ICU, 12.5% led to death. 3 cases but no control had previous TJA infection (p=0.033); 8 cases (40%) and 5 controls (12.5%) underwent same joint surgical procedure in the last year. 5 of 8 procedures in cases versus 1 of 5 in controls undergone while exposed to TNF blocker. In multivariate analysis, same joint surgical procedure during the last year was predictive of infection: OR=5.9 (95% CI, 1.2-30.3), p=0.03. Other predictive factors were: increased daily dose of steroids (OR=1.6 (1.1-2.3) p=0.01, per 5 mg/d increase) and increased duration of TJA (OR=1.2 (1.1-1.5) p=0.009 per 5 years). Conclusions: During a treatment with TNF blocker, TJA infection is rare but has a severe outcome. S. aureus is often involved. Recent TJA or TJA revision is a risk factor for TJA infection, in particular if surgery is performed in patients exposed to TNF blockers. Steroid intake, also predictive of infection, should be as low as possible in patients with TJA and TNF blocker.