Risk Factors for Surgical Site Infections in Spine Surgery with Vertebral Instrumentation: A Retrospective Study

Background: Surgical site infections (SSIs) are common and serious complications of spinal surgeries involving arthrodesis, contributing significantly to patient morbidity, mortality, and increased healthcare costs. Objective: To identify the risk factors associated with SSIs in patients undergoing spinal arthrodesis. Material and Methods: This observational and analytical study was based on a retrospective cohort of patients who underwent spinal surgery at two high-complexity hospitals in Medellín, Colombia. Results: Wounds classified as “contaminated” and “dirty” were associated with a significantly higher risk of infection (adjusted odds ratio [aOR] 11.71, P = 0.045; aOR 37.26, P = 0.002, respectively). Surgical re-intervention (aOR 2.74, P = 0.006) and intraoperative blood loss >500 cc (aOR 1.88, P = 0.036) were also identified as the significant risk factors. Conclusions: This study highlights the key risk factors for SSIs in spinal arthrodesis, including wound classification, need for reoperation, and excessive bleeding. Early recognition and targeted preventive strategies may help improve the postoperative outcomes.