Surgical Site Infections Following Posterior Lumbar Fusion

Introduction: It’s long been known that surgical site infections (SSIs) are a potential risk associated with undergoing spinal surgery. However, an intensified examination of this complication is both appropriate and warranted in light of the current medical landscape, including increasing antimicrobial resistance, significant SSI-associated economic implications, and the increasing proportion of elderly or complex patients undergoing spine surgery. It remains unclear if MIS techniques ultimately produce significantly decreased SSI rates in lumbar fusion surgery compared to open or mini-open. Therefore, the primary goal of this study was to investigate the difference in SSI rates for different surgical techniques in patients undergoing lumbar fusion.

Methods: This is a retrospective review of all patients who underwent 1 or 2-level instrumented posterior lumbar fusion between 01/2019 and 06/2022. Three cohorts (Mini, MIS, and Open) were created to divide patients based on the surgical technique utilized. Surgical Site Infections were identified according to the Centers for Disease Control and Prevention’s National Healthcare Safety Network (CDC/NHSN) criteria. Superficial SSIs involved only skin and subcutaneous tissue of the incision, Deep involved deep soft tissues of the skin (i.e., fascial and muscle layers), and Organ/Space involved surgeries in which a body part was opened or manipulated deeper than the fascial/muscle layers.

Results: A total of 1,382 lumbar fusion surgeries performed in 1,352 patients were included. The mean age was 61.5 ± 12.8 years, and the mean BMI was 28.7 ± 5.67 kg/m2. Of the 1,352 patients, 1,323 (97.9%) had one lumbar fusion surgery, 28 (2.1%) patients had 2, and 1 (0.1%) patient had 3 surgeries within the time period analyzed. The traditional open surgical technique was utilized in most of the surgeries (39.3%, 543), followed by Mini (33.1%, 458), and MIS (27.6%, 381). The overall SSI rate following lumbar fusion surgery was 0.94%. MIS cases had the lowest infection rate (0.3%, 1) followed by Mini (1.1%, 5) and Open (1.3%, 7). 13 patients developed an SSI, 2 were superficial, 5 were deep, and 6 were organ/space.

Conclusion : The overall SSI rate in our cohort was low; however, MIS cases had the lowest infection rate, followed by Mini-open and the traditional open technique.