Deep Surgical-Site Infection Following Thoracolumbar Instrumented Spinal Surgery: The Experience of 25 Years

Background: Deep surgical-site infection following thoracolumbar instrumented spinal surgery (DSITIS) is a major complication in spine surgery and its impact on long-term morbidity and mortality is yet to be determined. This article describes the characteristics and evolution of DSITIS in our center over a period of 25 years. Methods: This single-center, retrospective cohort study included patients diagnosed with DSITIS between January 1992 and December 2016 and with a minimum follow-up after infection diagnosis of 1 year. The Infectious Diseases Society of America criteria and/or Centers for Disease Control and Prevention criteria were used to define DSITIS. Patient data (epidemiological and health status), surgical data, infection characteristics and presentation, isolated microorganisms, required surgical debridements, implant removal, and major complications linked to infection were evaluated. Results: A total of 174 patients (106 females) were included in the analysis. Mean follow-up after infection diagnosis was 40 months (56 patients with over 5 years follow-up). Adolescent idiopathic scoliosis, adult deformity, and degenerative lumbar stenosis were the most frequent etiologies for primary surgery. Presentation of infection was considered early (0-3 months since first surgery) in 59.2% of the cases, delayed (3-24 months) in 11.5%, and late (more than 24 months) in 29.3%. All patients were treated by surgical debridement. More than 1 surgical debridement was necessary in 20.7% of cases. Implants were removed in 46.6% of the patients (72.83% in the first surgical debridement). Most frequently isolated microorganisms were Staphylococcus spp, Enterobacteriaceae, and Cutibacterium acnes. Major complications appeared in 14.3% of the patients, and over 80% of them required major surgeries to resolve those complications. Conclusions: Late DSITIS is more frequent than previously reported. In DSITIS culprits, Staphylococcus spp, Enterobacteriaceae, and Cutibacterium acnes predominate. DSITIS produce a high rate of major complications that usually require major surgery for treatment.