What to do if i broke my fibula, should i be in a cast or a moon boot?

CAM walker: Even though the fibula is an Non weight bearing bone, it is essential for the ankle joint. A removable cast below the knee would be your best option. Bones heal the fastest when no motion occurs across the fracture site. A fiberglass cast can be applied, but I think you would be happier with a removable CAM walker as long as it stays on all waking hours.....