Three-month antibiotic therapy for early-onset postoperative spinal implant infections

Abstract

Background: Optimal duration and modalities of antibiotic therapy for early-onset spinal implant infection (EOSII) remain controversial.

Methods: Between November 2004 and November 2007, we conducted a prospective, monocentric study to assess the efficacy of a 3-month course of antibiotics for patients diagnosed with EOSII, as defined by a proven deep infection of the surgical site occurring within 30 days after spinal instrumented surgery. All patients with EOSII underwent surgical debridement with implant retention. Combination antibiotic therapy was administered intravenously for 2 weeks. Treatment was switched orally for the following 10 weeks.

Results: 50 patients matched the inclusion criteria and were included in this study. The median age was 68 (interquartile range [IQR]: 51-75) years; the median ASA score was 2 (IQR: 2-2). Emergency spinal surgery had been performed in 18 patients. Staphylococcus aureus was the most frequently isolated pathogen (n=27), followed by Enterobacteriaceae (n=22) and coagulase-negative staphylococci (n=6). Seventeen patients had polymicrobial infections, and 13 patients (26%) had bacteremia. The median time from the first symptoms of infection to debridement surgery was 3 days (IQR: 2-5 days). Three patients underwent 2 debridement surgeries. The median follow-up was 43 (IQR: 34-54) months. The 2-year survival rate for those who did not experience treatment failure was 88% (95% confidence interval [CI]: 75.7%-95.5%). Three patients experienced treatment failure (6%, 95% CI: 1.3%-16.5%), including 1 relapse due to methicillin-susceptible S. aureus and 2 reinfections with another pathogen.

Conclusions: In this homogenous cohort of 50 patients with EOSII, treatment consisting of debridement surgery with implant retention followed by combination antibiotic therapy for 3 months appeared safe and effective.