Post Operative Infection following Posterior Cervical Spinal Instrumentation in the Vancomycin Powder Era

Introduction: Since the early 2010s, prophylactic vancomycin powder has become widely utilized in spine surgery, with many surgeons crediting its application for low surgical site infection (SSI) rates of 1-2%. However, some studies have questioned these statistics, and there remains a lack of consensus within the neurosurgical community regarding the effectiveness of vancomycin powder as a preventive measure.

Methods: The TriNetX Research Network was queried to identify adult patients who underwent single- or multi-level posterior spinal instrumentation with a preoperative diagnosis of cervical spinal stenosis, cervical disc disorder, cervical spondylosis, or cervical radiculopathy. Postoperative wound infections requiring incision and drainage, as well as other postoperative infections, were identified using corresponding procedural and diagnostic codes within 90 days following the index surgery. The patient population was divided into two groups: (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 matching was conducted based on age at surgery, gender, race, and selected comorbidities.

Results: A total of 21,586 patients met the inclusion criteria (mean age at surgery: 60.6 years [SD, 12.5]; 11,703 [54.22%] male), with 18,156 (84.11%) undergoing surgery between 2014 and 2023, and 3,430 (15.89%) between 2003 and 2013. Following propensity matching, each cohort included 3,427 patients, with no significant differences in age at surgery, gender, race, or selected comorbidities between the two groups. Among these matched cohorts, patients who underwent surgery between 2014 and 2023 had significantly lower odds of developing postoperative infection (OR = 0.656) and similar odds of requiring incision and drainage for postoperative wound infection (OR = 1.092) compared to those who had surgery between 2003 and 2013.

Conclusion : This large-scale, retrospective, propensity-matched analysis reveals that the odds of developing a postoperative infection following posterior cervical spinal instrumentation are approximately 35% lower in the era of prophylactic vancomycin powder, while the rates of incision and drainage for postoperative infection remain consistently low at 0.6-0.7%. These findings suggest that prophylactic vancomycin powder is an effective measure for reducing postoperative infection rates in spine surgery, reinforcing its role in enhancing surgical outcomes.