Risk factors of surgical site infections in instrumented spine surgery

BACKGROUND The incidence of wound infections associated with instrumented spine surgery ranges from 2 to 20%. These complications may lead to poor outcomes. Knowing the risk factors associated with surgical site infections (SSI) after utilizing spinal implants is essential to avoid these complications, including hardware removal. METHODS We reviewed retrospectively 550 patients who underwent spinal fusion surgery from 2011 to 2015; 16 developed SSI after spinal instrumentation. The diagnosis of SSI was established based on positive wound swab or blood cultures, and various clinical, laboratory, and radiological findings. Additional preoperative and intraoperative risk factors were analyzed. RESULTS The incidence of SSI after spinal instrumentation surgery was 2.9%. Obesity was a statistically significant parameter (P = 0.013) that contributed to SSI along with the alcoholism and/or drug abuse (P = 0.034); use of a Foley catheter nearly reached significance levels. CONCLUSIONS There is an increased risk of SSI in patients who are obese or use drugs and/or alcohol. Clear preoperative identification of these risk factors prior to implanting spinal instrumentation should help prevent SSI in the future.