Predictors of treatment outcome in prosthetic joint infections treated with prosthesis retention

Purpose The reported success rates of debridement, antibiotics, and implant retention (DAIR) for prosthetic joint infections (PJIs) vary widely. Several risk factors have been described for treatment failure, but they vary between studies. The purpose of this study was to evaluate the predictors of DAIR failure in PJI treatment and to assess the efficacy of rifampin combined with ciprofloxacin versus rifampin combined with other antibiotics in staphylococcal PJIs. Methods Patients with PJI that underwent DAIR for the first time between February 2001 and August 2009 were identified retrospectively in the hospital's patient databases. A total of 113 PJI cases with early postoperative or acute haematogenous PJI were followed for up to two years from the start of treatment. Results In univariate analysis, variables significantly associated with treatment failure were acute haematogenous infections (p = 0.022), leucocyte count at admission > 10 x 10(9)/l (p < 0.01), pain in the joint (p < 0.01), and ineffective empirical antibiotics (p < 0.01). In a multivariate Cox model, leucocyte count > 10 x 10(9)/l and ineffective empirical antibiotics were significant risk factors for failure. Compared to rifampin-ciprofloxacin, the hazard ratio (HR) for treatment failure was significantly increased in the rifampin-other antibiotics group (HR 6.0, 95 % CI 1.5-28.8, p = 0.014) and the group treated without rifampin (HR 14.4, 95 % CI 3.1-66.9, p < 0.01). Conclusions Rifampin-ciprofloxacin combination therapy was significantly more effective than rifampin combined with other antibiotics. Effective empirical antibiotics are essential for successful PJI treatment.