Prevention of Surgical Site Infection in Lumbar Instrumented Fusion Using a Sterile Povidone-Iodine Solution

BACKGROUND: Surgical site infection (SSI) is a well documented complication in patients who undergo posterior spine instrumentation with most studies reporting an incidence of 1%-12%. Some studies have documented that a diluted sterile povidone-iodine (PVI) solution can be safely used in posterior spinal fusion surgeries as an antiseptic; in this study, we analyzed its effectiveness in reducing SSI. METHODS: This retrospective study consisted of consecutive patients who underwent elective posterior lumbar instrumentation performed by a single surgeon from 2016 to 2019. In the first 134 patients, wounds were irrigated before arthrodesis and closure with 1 L of 0.9% normal saline solution; in the subsequent 144 patients, wound irrigation was with a solution of 35 mL of sterile 10% PVI. Both groups were analyzed to determine if wound irrigation with sterile PVI solution decreased SSIs. RESULTS: There were 9 (6.7%) SSIs in the 0.9% normal saline solution group versus 1 (0.7%) SSI in the PVI group (P = 0.008). PVI solution had a relative risk for SSI of 0.093 (P = 0.008) and an adjusted odds ratio of 0.113 (P = 0.05). Increased body mass index and posterolateral spine fusion with laminectomy were significant risk factors for SSI (P = 0.04 and P = 0.030, respectively). CONCLUSIONS: Wound irrigation with PVI solution significantly reduced SSI in elective posterior lumbar & nbsp;instrumentation cases. Subgroup analysis provided significant results to recommend use of PVI solution for SSI prevention, particularly in overweight and obese patients. We also recommend its use in patients with risk factors for SSI, such as longer operative time and unintended durotomy.