The splinting manual given before is good. If it's the ankle then you are probably going to have to do a shoe splint with support going up the lower leg to keep it positioned properly. The manual also explains how to examine for a fracture. Even if it doesn't heal absolutely perfectly it may be enough to give him quality of life. Alternately you can seek vet care if that is an option for you.
Hens go broody when you don’t want them to… and won’t go broody when you do. 