Risk factors for postoperative spinal infection: A retrospective analysis of 5065 cases

BACKGROUND: Multiple factors increase the risk for spinal surgical site infection (SSI): prior SSI, obesity, diabetes mellitus, advanced age, American Society of Anesthesiologists class, alcohol abuse, low prealbumin levels, smoking, history of cancer, chronic steroids, immunosuppressive drugs, rheumatoid arthritis, and hypothyroidism. METHODS: Here, we performed a retrospective medical record review at one facility involving 5065 patients from 2010 to 2015. In 2011, there was an increase in the infection rate (1.07%) which prompted this analysis, resulting in the subsequent introduction of a protocol to reduce the infection risk. RESULTS: The overall infection rate in this series was 0.59%. The lowest infection rate was 0.00% for anterior cervical discectomy and fusion. The highest rate of infections occurred among patients undergoing posterior cervical fusions, lumbar fusions, and tumor resections. Higher infection rates were also correlated with diabetes mellitus, obesity, and increased surgical time. CONCLUSIONS: Since 2011, we instituted a protocol to limit the risks of spinal SSIs, particularly for patients exhibiting increased medical comorbidities.