Open fractures
Open fractures are a problem as they allow germs to get into the bones and prevent healing. If you are faced with a wound with a piece of sharp bone sticking out, simply place a sterile first aid dressing over it and support the limb. If there is significant active bleeding from the wound, then simply press on it to stem the flow, again with a sterile dressing. This will turn an open fracture into a closed fracture.