Comparison of postoperative infection risk with and without topical vancomycin in adult posterior spinal fusion: a propensity-matched cohort study of 126,910 patients

The TriNetX Global Collaborative database was queried to identify adult patients undergoing PSF. Patients were stratified into two cohorts based on documented administration of topical vancomycin and systemic cefazolin (topical cohort) versus systemic cefazolin alone (control cohort). Patients underwent 1:1 propensity matching based on demographics and relevant comorbidities. The primary outcomes of interest included 90-day rates of infection-related complications. Subgroup analyses were performed to identify the influence of neuromuscular scoliosis, PSF with osteotomies, pelvic fixation, or fusion of greater than six levels on infection rates. Infectious complication rates were also compared between patients receiving topical vancomycin with and without topical gentamicin or tobramycin.

After propensity matching, 63,455 patients were included in each cohort. Patients in the topical cohort demonstrated comparable rates of overall infection (3.0% vs. 3.1%, p = 0.794), superficial surgical site infection (SSI) (0.9% vs. 0.8%, p = 0.151), deep SSI (0.6% vs. 0.6%, p = 0.070) and all other infectious complications when compared to the control cohort. Subgroup analysis revealed decreased rate of deep SSI when using topical gentamicin or tobramycin with vancomycin versus topical vancomycin alone (0.7% vs. 1.7%, p = 0.019). No other between-group differences were observed.