Post Operative Infection Following Multi-level Posterior Lumbar Spinal Instrumentation in the Vancomycin Powder Era

Introduction: Since the early 2010s, the use of prophylactic vancomycin powder has become commonplace in spine surgery, with many surgeons attributing low surgical site infection (SSI) rates (1-2%) to its application. However, some studies have challenged these estimates, and there remains ongoing debate within the neurosurgical community regarding the true efficacy of prophylactic vancomycin powder use.

Methods: The TriNetX Research Network was queried to identify adult patients who underwent posterior spinal instrumentation at three or more levels with a preoperative diagnosis of lumbar spinal stenosis or spondylolisthesis. The patient population was divided into two cohorts: (1) those who underwent surgery between January 1, 2003, and December 31, 2013, and (2) those who underwent surgery between January 1, 2014, and December 31, 2023. Propensity score matching (PSM) was performed based on demographics and selected comorbidities. The composite rate of postoperative infection, encompassing infection following the procedure, superficial incisional SSI, deep incisional SSI, organ and space SSI, and procedure-related sepsis as well as postoperative wound infections requiring incision and drainage (I&D) were identified through corresponding procedural and diagnostic codes within 90 days of surgery

Results: A total of 30,362 patients met the inclusion criteria (mean age at surgery: 63.8 years [SD, 11.0]), with 26,225 (86.37%) undergoing surgery between 2014 and 2023, and 4,137 (13.63%) between 2003 and 2013. After PSM, each cohort contained 4,135 patients. Among these matched cohorts, patients who underwent surgery between 2014 and 2023 had significantly lower odds of requiring I&D (OR = 0.553, 95% CI [0.322, 0.939]) and of developing postoperative infections (OR = 0.489, 95% CI [0.378, 0.633]) within 90 days of surgery.

Conclusion : This large-scale, propensity-matched analysis indicates that the likelihood of developing a postoperative infection or requiring I&D following multi-level posterior lumbar spinal instrumentation is approximately 50% lower during the era of vancomycin powder use compared to the period before its widespread adoption. These findings suggest that prophylactic vancomycin powder may be an effective strategy to reduce postoperative infections in patients undergoing multi-level posterior lumbar spinal instrumentation.