I am a mechanical engineer and I actually worked on a Rib Plating system at my old job, so I know a decent amount about how they treat it. In most cases, for a cracked rib, they don't do anything. It does hurt a good amount for awhile, but they normally just let it heal. The only time that they decide to go in and use titanium plates, such as the ones I worked on, is if a patient comes in as a trauma and has a completely collapsed chest wall. They will plate the ribs while trying to re-establish the chest cavity because it will make it more stable and allow the patient to heal much faster. At this point, rib plating is a fairly new procedure and it is not being used in all cases because under normal circumstances, your rib can heal on its own.