The prevention of infection is an important goal influencing peri-operative care of extremity fracture patients. Standard practice in the operative management of extremity fractures includes sterile technique and pre-operative skin preparation with an antiseptic solution. The available solutions kill bacteria and decrease the quantity of native skin flora, thereby decreasing surgical site infection (SSI). While there is extensive guidance on specific procedures for prophylactic antibiotic use and standards for sterile technique, the evidence regarding the choice of antiseptic skin preparation solution is very limited for extremity fracture surgery.

More than one million Americans suffer an extremity fracture (broken bone in the arm, leg, or pelvis) that requires surgery each year. Approximately 5% (or 50,000) of surgical fracture patients develop a surgical site infection (SSI), which is twice the rate among most surgical patients and nearly five times the rate among patients undergoing elective orthopaedic surgeries (e.g. joint replacement). Patients who develop a SSI after their fracture fixation surgery experience a long and difficult treatment pathway. Researchers have identified that when a fracture patient experiences a SSI, they typically undergo at least two additional surgeries to control the infection, spend a median of 14 additional days in the hospital, and have significantly lower health related quality of life (HRQL). Similarly, results from the recently completed Fluid Lavage of Open Wounds (FLOW) trial confirmed that patients who had a SSI, or another complication, that required an additional surgery reported significantly lower physical and mental HRQL in the 12 months following their fracture compared to patients who did not experience a SSI. In the most severe cases, when a SSI cannot be controlled, a limb amputation becomes necessary.

Open fractures, closed lower extremity fractures, and pelvic fractures represent some of the most severe musculoskeletal injuries. Due to their high-energy mechanisms, these fractures are often accompanied by soft-tissue injuries that contribute to unacceptably poor outcomes. The FLOW trial of 2,447 open fracture patients reported a 13.2% incidence of open fracture-related reoperations; Closed fractures of the lower extremity are also at high risk of complications, particularly when compared to closed upper extremity fractures. For example, the rate of SSI in closed tibial plateau and plafond fractures range from 5.6 - 11.9%, although some cohort studies have reported infection rates as high as 25.0%. This is contrast with SSI rates of <5% for common upper extremity fractures like humeral shaft, forearm, or distal radius fractures. This is further illustrated in a series of 214 deep orthopaedic fracture infections, in which 58% occurred in the tibia and ankle, and only 10% occurred anywhere in the upper extremity. Finally, pelvic fractures are associated with some of the most challenging SSIs to treat among closed fractures because of their propensity to gram negative organisms and limitations in reconstruction options post-infection. Ultimately, infectious complications in these fracture populations lead to prolonged morbidity, loss of function, and potential limb loss.

The open fracture inclusion criteria are:

1. Patients 18 years of age or older.
2. Open fracture of the appendicular skeleton.
3. Received or will receive definitive fracture treatment with a surgical implant(s) (i.e., internal fixation, external fixation, joint prosthesis, etc.).
4. Open fracture wound management that includes formal surgical debridement within 72 hours of their injury.
5. Will have all planned fracture care surgeries performed by a participating surgeon or delegate.
6. Informed consent obtained.
7. Patient enrolled within 3 weeks of their fracture.

The open fracture exclusion criteria are:

1. Fracture of the hand (distal to radial carpal joint).
2. Patients who did not or will not receive the allocated pre-operative surgical preparation solution due to a medical contraindication.
3. Received previous surgical debridement or management of their fracture at a nonparticipating hospital or clinic (as applicable).
4. Open fracture managed outside of the participating orthopaedic service (e.g., foot fracture managed by podiatrist).
5. Chronic or acute infection at or near the fracture site at the time of initial fracture surgery.
6. Burns at the fracture site.
7. Incarceration.
8. Expected injury survival of less than 90 days.
9. Terminal illness with expected survival less than 90 days.
10. Currently enrolled in a study that does not permit co-enrollment.
11. Unable to obtain informed consent due to language barriers.
12. Likely problems, in the judgment of study personnel, with maintaining follow-up with the patient.
13. Prior or current enrollment in a PREP-IT trial.
14. Enrolled in the PREPARE closed cohort.
15. Excluded due to sampling strategy.

The closed fracture inclusion criteria are:

1. Patients 18 years of age or older.
2. Closed fracture of the lower extremity or pelvis.
3. Received or will receive definitive fracture treatment with a surgical implant(s) (i.e., internal fixation, external fixation, joint prosthesis, etc.).
4. Fracture management requires a surgical incision (i.e., for fracture reduction or implant insertion).
5. Will have all planned fracture care surgeries performed by a participating surgeon or delegate.
6. Informed consent obtained.
7. Patient enrolled within 6 weeks of their fracture.

The closed fracture exclusion criteria are:

1. Patients who did not or will not receive the allocated pre-operative surgical preparation solution due to a medical contraindication.
2. Received previous surgical management of their fracture at a non-participating hospital or clinic.
3. Fracture managed outside of the participating orthopaedic service (e.g., foot fracture managed by podiatrist).
4. Chronic or acute infection at or near the fracture site at the time of initial fracture surgery.
5. Burns at the fracture site.
6. Incarceration.
7. Expected injury survival of less than 90 days.
8. Terminal illness with expected survival less than 90 days.
9. Currently enrolled in a study that does not permit co-enrollment.
10. Unable to obtain informed consent due to language barriers.
11. Likely, problems, in the judgment of study personnel, with maintaining follow-up with the patient.
12. Prior or current enrollment in a PREP-IT trial.
13. Enrolled in the PREPARE open cohort.
14. Excluded due to sampling strategy.

The orthopaedic team (including the study coordinators) cannot be blinded to the treatment allocation as the antiseptic solutions are visually distinguishable and these individuals need to lead the implementation of the cluster-crossover protocol at their clinical site. The Adjudication Committee Members and data analysts will be blinded to the study treatment. All interpretation of study results will initially be done in a blinded manner by developing two interpretations of the results. One interpretation will assume treatment A is iodine povacrylex, the other interpretation will assume it is CHG. Once the data interpretations for each assumption are finalized, the data will be unblinded and the correct interpretation will be accepted.