Yes the mechanism of injury is very rare. I've never heard of this happening before anywhere. Yet I'm fairly confident that there was no pre-existing injury. Both parents are medical professionals with extensive musculoskeletal backgrounds. The kid is a LL player, not a year round player. It may could be that the kid's body type pre-disposed him to some shoulder instability and led to this type of injury, but then why doesn't this happen more often?
Anyway, and regardless of how it happened, the kid is facing some significant life changes. Surgery is a big deal here, and since baseball was a big deal before the injury, I'm wondering if he has any chance of pursuing it further.
Because the injury occurred when swinging, I doubt that he could ever again be an effective hitter- it's too likely that this event will always be lurking in the back of his head when swinging and I don't see how he could ever regain the aggressiveness. But if the surgery and rehab go well, he could *possibly* pitch again.
Baseball could be a great motivator in rehab. Then again if there's little or no chance of him throwing competitively again then it's just irresponsible to even allow the kid to hope of playing baseball ever again.
I don't know any kids who've gone through this before. That's why I'm asking. Maybe the best advice will ultimately come from his surgeon, but unless he has a baseball background then I'm afraid he'll just tell the kid to pick up soc*er. I'm trying to help the parents be honest and realistic. What would you tell them?