Elbow dislocations are a common arm injury and they often happen with breaks at the same time. For this reason, there are a few things that need to be repaired and monitored. Most often, a dislocation can be put back into place (reduced) with just some local anesthetic and then the arm is braced or casted for healing. If the dislocation is complicated or, for some reason, won’t respond to that type of reduction, the doctor may have to opt for an open reduction, which is done in surgery.
However, surgery requires a general anesthetic and surgeons are reluctant to use if it’s not necessary. General anesthetic has risks of its own. Without knowing exactly what happened, it is likely that once they got to the operating room, the surgeons had your son in a relaxed state and decided to try one more time at reducing the fracture and elbow before preparing for the surgery.