This study is testing a new way to give medicine for bad open bone breaks in the leg and ankle. The new plan, called SEXTANT, is compared to the usual treatment. A Type III open fracture is a severe break with a wound that exposes the bone. The study checks if the new plan can lower infection rates at the surgery site and if it causes fewer serious side effects. It also looks at using fast tests to find germs in the wound.

• The study is for adults aged 18-64 with severe leg or ankle fractures.
• Patients with certain health conditions like diabetes or brain injury can join.
• Patients with other injuries or who have started treatment elsewhere may still be eligible.

People cannot join if they have an ongoing infection at the study site, or if it's hard for them to come back for check-ups. The study involves comparing the two treatment methods by looking at the infection rates and any side effects. Participants will help understand if the new treatment is better for severe fractures.