Safety and Efficacy of Subdermal Betadine During Posterior Spinal Fusion

This is a prospective, one site, randomized controlled trial. The goal of this project is to evaluate the efficacy of subdermal 10% povidone-iodine at reducing bacterial contamination from the subdermal layer of skin during posterior spinal fusion. The primary outcome of this study will be incidence of positive bacterial growth in several layers of the surgical wound. Secondary outcomes will be complications, including allergic reactions, contact dermatitis, surgical site infection and wound complications. Finally, patient and surgical variables that can effect microbial growth will be observed.

Once identified, the surgeon and coordinators will discuss risks, benefits, advantages, and disadvantages of this study to eligible patients. If the family wishes to enroll, the patient's family and patient will be consented. And automatically randomized to either povidone-iodine vs control group (predetermined according to the statistician). All patients will follow the standardized spine pathway including standard antibiotics and skin preparation with isopropyl alcohol followed by ChloraPrepTM and sterile draping. Five bacterial cultures will be obtained throughout the spinal fusion similarly for all patients by rubbing along the entirety of the posterior spinal incision. The first two cultures will be taken before the placement of an antimicrobial adhesive drape and after the initial incision in the subdermal layer. The surgeon will be notified which group the patients are in. Patients who were randomized to the povidone-iodine group will then have three topical applications of 10% povidone-iodine along the length of the subdermis, using each of the 3 swab sticks provided from the sterile single-use packet. Patients who were randomized to the control group will then have three applications of sterile saline along the length of the subdermis, using each of the 3 swab sticks soaked in sterile saline. Following the 10% povidone-iodine or saline application, the solution will be allowed to dry at least three minutes and a third culture will be obtained. Surgical exposure will proceed in all patients, and an additional culture will be obtained along the length of the deep wound after exposure, and a final culture along the length of the deep wound just prior to wound closure. The swabs will be cultured, and the final results will be reported however, the surgeons delivering patient care will be blinded to the results to mitigate competing interests. Routine postoperative care will follow standard of care no matter the culture results. A data safety monitor will assure no correlation between culture results and infection rate.

Inclusion criteria

• Males and females
• Undergoing primary posterior spinal fusion of the thoracic and/or lumbar spine
• English Speaking

Exclusion criteria

• Patients who have undergone prior spinal surgery
• Undergoing procedures other than primary posterior spinal fusion of the thoracic and/or lumbar spine (cervical fusion, anterior surgery, growth-friendly instrumentation)
• Any contraindication to povidone-iodine, including pregnancy, allergy, or prior treatment with radioiodine