The management and outcome of spinal implant infections: Contemporary retrospective cohort study

Background. Spinal implant infections provide unique diagnostic and therapeutic challenges. Methods. We conducted a retrospective cohort study to evaluate risk factors for treatment failure in patients with early- and late- onset spinal implant infections at the Mayo Clinic (Rochester, MN) during 1994-2002. Results. We identified 30 patients with early-onset spinal implant infection and 51 patients with late-onset spinal implant infection. Twenty-eight of 30 patients with early-onset infection were treated with debridement, implant retention, and antimicrobial therapy. The estimated 2-year cumulative probability of survival free of treatment failure for patients with early-onset infection was 71% (95% confidence interval [CI], 51%-85%). Thirty-two of 51 patients with late-onset infection were treated with implant removal. Their estimated 2-year cumulative probability of survival free of treatment failure was 84% (95% CI, 66%-93%). For patients with early-onset infections, receiving oral antimicrobial suppression therapy was associated with increased cumulative probability of survival (hazard ratio, 0.2; 95% CI, 0.1-0.7). For patients with late-onset infections, implant removal was associated with increased cumulative probability of survival (hazard ratio, 0.3; 95% CI, 0.1-0.7). Conclusions. Early-onset spinal implant infections are successfully treated with debridement, implant retention, and parenteral followed by oral suppressive antimicrobial therapy. Implant removal is associated with successful outcomes in late-onset infections.