There are many methods in the bone doctor's bag of tricks, which one is used depends on the type of fracture. For bad fractures, fixation methods must be used like plates, screws and rods. But for simple broken bones, a cast of plaster is all that's needed.
The familiar Plaster of Paris cast is a chemical which when water is added turns from a soft powder to a hard shell which can hold your bones in shape - like mild cement. The bone is first manipulated straight, then a thin layer of cotton padding is wrapped around your broken bone to keep the hard plaster away from your skin, then the plaster is applied. Is soon feels very warm as it chemically sets hard.
Before and after any procedure an X-ray of the bone is taken. The first to prove that there's a break, how bad it is, and exactly where it is. The second to make sure you've got it correct. Once the bone doctor is happy with the second X-ray they can let you go home to be reviewed again in their clinic several weeks later. Here again an X-ray may be taken to observe healing progress and the cast taken off to look at the area. Once your doctor is satisfied then there's no more need for a cast. It's up to you then to exercise the limb that's been resting several weeks. And you can display your old cast with friend's signatures all over it as a trophy in your bedroom.
Most of the time when a bone breaks the two ends move past or away from each other. This is because of the force that caused the damage pushing around the bones and because the muscles attached to the bones are pulling them away.
While you're lying down, your bone doctor will stand at one end of the broken bone and an assistant at the other. They will then pull in a straight line until they feel the bones snap back in place or can see that the protruding bone ends have flattened. Of course you won't be howling through this in pain because you'll be sedated through drugs given by an intravenous line or injection.
Once the bone doctor is happy with the alignment of the bone, they'll then wrap a cast around it to hold it in place and send you for a new X-ray to compare with the first to make sure the ends are holding. One happy, the cast is then left on for a month then rechecked.
Fracture Surgical Treatment
There are 2 types: inside and outside the bone fixation. Both are surgical methods.
Outside (external) fixation is shown in our cartoon above at A. You're seeing some pins driven into the bone from outside the skin to hold the broken bones together. This method is preferred in open fractures (because using types B & C will risk infection through the gaping wound) and comminuted fractures - because you can put as many pins in as you need. Once the bone has fused, the pins are taken out and discarded.
Inside (internal) fixation is shown in B as a rod pushed down the center of the bone, and as C, a plate with screws going into the two ends of the bone. Both of these methods are used in broken bones that will not stay together and where there's no open skin wound. For B, the skin over the top of the bone is surgically slit and with a special hammer the nail is beaten down from the top, through the center of the bone, down through the crack, into the other end. It is left in the bone permanently strengthening it. In type C The skin over the crack(s) is also surgically slit and the 'hardware' introduced and screwed in one side of the bone over the crack. It too is left in.