Large multicenter clinical trial finds that antiseptic containing iodine reduces surgical-site infections in patients with extremity fractures

The study -- which compared the two most commonly used alcohol-based solutions, one with iodine povacrylex, and the other with chlorhexidine gluconate -- may prompt changes in the type of antiseptic orthopaedic surgeons use to prepare the skin to repair fractures. Researchers saw the benefit in patients with closed, or simple fractures, where the skin remains intact, but not in compound fractures with open wounds, although they noted that using the iodine preparation was not harmful to these open-fracture patients.

"Our results suggest that the use of iodine povacrylex in alcohol as a preoperative skin antiseptic could prevent surgical-site infections in thousands of patients with closed fractures each year," said co-principal investigator Gerard Slobogean, MD, MPH, an Associate Professor of Orthopaedics and Director of Clinical Research in the Department of Orthopaedics at the University of Maryland School of Medicine (UMSOM). He is also an orthopaedic trauma surgeon at the R Adams Cowley Shock Trauma Center at the University of Maryland Medical Center (UMMC).

Each year, more than a million Americans suffer a broken bone in the arm, leg, or pelvis that requires surgery, and about 3 percent of these patients develop a surgical-site infection. The source of bacteria could be the patient's skin, the injury environment, or from the hospital. Although some guidelines have favored using chlorhexidine gluconate over other iodine products, there has not been a consensus on the most effective agent.

Dr. Slobogean and his colleagues believe that the trial, which included 8,485 patients treated at 25 trauma centers, is the largest randomized clinical trial ever conducted to compare the two antiseptics, which allowed them to detect important differences in infection. They said that the findings may also be relevant to other surgical specialties.

More than 6,700 patients who had surgery to treat a closed lower extremity or pelvic fracture and 1,700 patients who had surgery to treat an open fracture participated in the study.

The R Adams Cowley Shock Trauma Center and University of Maryland Capital Region Health's (UM Capital) trauma center in Largo, Md., were among more than two dozen trauma centers to enroll patients. UMMC and UM Capital are part of the 11-hospital University of Maryland Medical System (UMMS).

"The results of this well-designed study provide some long overdue clarity to orthopaedic trauma surgeons with respect to which commonly used antiseptic skin preparation is more effective when preparing for fracture surgery," said study co-author Todd Jaeblon, DO, an Associate Professor of Orthopaedics at UMSOM who treats patients at UM Capital.

Of the 3,205 closed-fracture patients who received 0.7% iodine povacrylex in 74% isopropyl alcohol, 77, or 2.4 percent, developed a surgical-site infection. That compares with 108, or 3.3 percent of the 3,272 patients who received 2% chlorhexidine gluconate in 70% isopropyl alcohol. In patients with open fractures, the number of patients who developed infections was similar between the two antiseptics -- 54 patients, or 6.5 percent of 825 patients in the iodine group, and 60 patients, or 7.3% of the 826 patients in the chlorhexidine group.

"Extremity fractures and the challenging surgical-site infections that result from them pose a significant health care burden on our nation," said Mark T. Gladwin, MD, who is the John Z. and Akiko K. Bowers Distinguished Professor and Dean, UMSOM, and Vice President for Medical Affairs, University of Maryland, Baltimore. "This pragmatic trial tested two widely used antiseptics, and its crossover design minimized selection bias. It also enrolled patients from 25 diverse hospitals in the U.S. and Canada, which improved the generalizability of the results; the strength of the study design could serve as a model for other researchers."

The PREPARE (Pragmatic Randomized Trial Evaluating Preoperative Alcohol Skin Solutions in Fractured Extremities) trial was jointly led by UMSOM and McMaster University of Hamilton, Ontario. It was funded with $11.2 million from the Patient-Centered Outcomes Research Institute (PCORI), with additional support from the Canadian Institutes of Health Research.

"This trial represents a highly successful collaboration between McMaster University, the University of Maryland School of Medicine, and 25 trauma centers across Canada and the United States," said co-principal investigator Sheila Sprague, PhD, an Associate Professor and Research Director at McMaster University. "This multidisciplinary approach allowed us to quickly and efficiently address an important clinical research question that will lead to the prevention of thousands of infections each year. Importantly, our collaborations will continue to grow to address other unanswered questions in orthopaedic trauma surgery."

This is the second clinical study co-led by Dr. Slobogean and Dr. Sprague aimed at closing the gaps in the medical literature on the most effective infection-control techniques in orthopaedic surgery. In October 2022, they published the results of the Aqueous-PREP trial in The Lancet. They concluded that the choice of an aqueous antiseptic solution -- either 10% povidone-iodine or 4% chlorhexidine gluconate -- does not alter the risk of surgical-site infection for patients with an open fracture.

Both Aqueous-PREP and PREPARE follow a master protocol called PREP-IT (Program of Randomized Trials to Evaluate Preoperative Antiseptic Skin Solutions in Orthopaedic Trauma) to test infection prevention techniques in trials that will provide crucial evidence to help guide surgical practices.

This research was supported by the PREP-IT investigators, which includes a network of over 200 physicians, allied health care professionals, trauma patients, and clinical researchers.