Post-spinal surgery infections: a two-year follow-up study on risks, resistance, and recovery.

BACKGROUND: Surgical site infections following spinal surgery (SSI-SS) are a major concern, leading to increased morbidity, prolonged hospital stays, and higher healthcare costs. This study aimed to analyze the epidemiology, microbiological characteristics, and treatment outcomes of SSI-SS at La Timone Hospital, Marseille, from 2016 to 2022. METHODS: We conducted a retrospective cohort study of patients with microbiologically confirmed SSI-SS. Demographic data, bacterial pathogens, antimicrobial resistance profiles, and treatment outcomes were analyzed over a two-year follow-up period. RESULTS: Among 6,975 spinal surgery patients, 227 (3.3%) developed SSI-SS. The most commonly isolated pathogens were Staphylococcus aureus (40%)—8% of which were methicillin-resistant (MRSA)—and Enterobacteriaceae (35%), with 23% being multidrug-resistant. Surgical revision was required in 98% of cases, with debridement and osteosynthesis retention as the preferred approach. Immunosuppressive condition (HR 2.58 [1.3, 4.8], p = 0.005) and tumor resection (HR 2.4 [1.3–4.5], p = 0.007) were independently associated with poor outcomes. The use of rifampicin (HR 0.3 [0.1–0.7], p = 0.008) or clindamycin (HR 0.2 [0–0.9], p = 0.009) in antimicrobial targeted therapy was significantly linked to improved recovery rates. Despite cefazolin prophylaxis, 3.3% of patients still developed infections, raising concerns about its effectiveness. CONCLUSION: Our findings highlight the high burden of antibiotic-resistant infections in SSI-SS and suggest that rifampicin or clindamycin-based regimens may improve patient outcomes. The efficacy of standard prophylaxis with cefazolin warrants further investigation, and alternative preventive strategies should be considered.