Experience With Intrawound Vancomycin Powder for Spinal Deformity Surgery

Study Design. Retrospective cohort study. Objective. To evaluate the ability of local vancomycin powder to prevent deep wound infection after thoracolumbar and lumbar spinal fusion for open deformity cases. Summary of Background Data. Recent studies report that local delivery of vancomycin powder is associated with a decrease in spinal surgical site infection (SSI). This study compares deformity fusion cases before and after the routine application of spinal vancomycin powder. Methods. Posterior spinal deformity surgical procedures by a single institution were reviewed from January 2011 to April 2013. Routine application of vancomycin powder started in April 2012. Inclusion criteria included adult patients who underwent posterior fusion for deformity pathologies, including spondylolisthesis, kyphosis, sagittal imbalance, and scoliosis. Each cohort's baseline characteristics including infection risk factors, operative data, and rates of wound infection were compared. Associations between infection and vancomycin powder, with and without propensity score adjustment for risk factors were determined using logistic regression. Results. A total of 306 patients were included in the study. All measured baseline and operative variables were statistically similar between untreated (n = 150) and those who received vancomycin powder (n = 156). No significant change in deep wound infection rate was seen between the control (5.3%) and intervention group (5.1%, P = 0.936). Logistic regression with and without propensity score adjusted for risk factors demonstrated that the use of vancomycin powder did not impact the development of SSI (odds ratio [95% confidence interval]: 1.01 [0.36-2.79], P = 0.9910) and (odds ratio [95% confidence interval]: 0.87 [0.31-2.42], P = 0.7876), respectively. Conclusion. The local application of powdered vancomycin was not associated with a significant difference in the rate of deep SSI after spinal deformity surgery, and other treatment modalities are necessary to limit infection for this high-risk group. This study is in contrary to prior studies, which have reported a decrease in SSI with vancomycin powder.