Without knowing what exactly happened to your son’s elbow, it’s not possible to give you a specific answer. Usually, elbows are so well protected that repeat dislocations aren’t a problem. That being said, that doesn’t sound like your son’s situation. Has your son gone to see any other orthopedic doctor since he has reached adulthood? It may be worth having the arm examined and perhaps re-x-rayed to see if there is anything that can be done to help stabilize it