Randomized, Prospective Study of the Order of Preoperative Preparation Solutions for Patients Undergoing Foot and Ankle Orthopedic Surgery

Abstract

Background: Surgical site infection is routinely cited as the most common complication following orthopedic foot and ankle surgery. Our institution uses 4% chlorhexidine gluconate followed by 70% isopropyl alcohol to reduce skin bacterial loads prior to surgery. These solutions have potential synergistic qualities to prevent a postoperative infection. The purpose of this study was to determine if the order of these solutions has a significant effect on the residual bacterial pathogens load following operative site preparation for foot and ankle surgery, as evidenced by positive culture swabs. Methods: A total of 95 consecutive patients, undergoing surgery of the foot and ankle with a single surgeon, were prospectively randomized to 1 of 2 operative preparation groups: isopropyl alcohol (IPA) group, whose operative site preparation consisted of a 4% chlorhexidine application followed by alcohol rinse (49 patients), and chlorhexidine gluconate (CHG) group, which had 46 patients undergo operative site preparation using alcohol followed by chlorhexidine. A total of 4 aerobic culture specimens were obtained from the third web space of the operative foot on each patient: (1) prior to operative site preparation, (2) after the prep was completed, (3) after completion of the procedure, and (4) after the incision was closed. Each patient was then followed for 6 months postoperatively to monitor the operative site. Medical comorbidities were also analyzed. Results: The average time for IPA procedures was 52 minutes vs 54 for CHG (ns). There was no difference between groups with respect to diabetes, tobacco use, obesity, race, or immunosuppression. Both groups had 100% bacterial growth from specimens obtained prior to operative site preparation ( P > .05). For all postpreparation swabs, 19.0% (28/147) of the IPA cultures were positive compared to 10.9% (15/138) from the CHG group cultures ( P = .07). The amount of patients with positive culture results favored the CHG group at each collection point: 6.5% (3/46) versus 25% (12/49) after draping ( P = .02); 15% (7/46) versus 33% (16/49) after completion of the surgery ( P = .05); and 20% (9/46) versus 35% (17/49) after skin closure ( P = .07). One operative site infection was seen in the first 30 days following surgery for each treatment group, each treated with oral antibiotics. No additional skin or wound complications were encountered during the 6-month study follow-up. Conclusion: Postoperative infection rates following foot and ankle orthopedic surgery was low. Both chlorhexidine and isopropyl alcohol solutions were effective methods in reducing operative site bacterial colonization when combined. In this study, applying isopropyl alcohol solution followed by the chlorhexidine solution was more effective in reducing positive bacterial cultures taken after operative site preparation. No difference in clinical wound infection rate was seen. Level of Evidence: Level I, prospective randomized study.