Posted this on another thread. It is a good explanation of what he has and how it is treated
https://www.youtube.com/watch?v=zoBuze8nA-A
Friend of mine who is an orthopedic surgeon thinks most likely if it is truly a 3rd degree tear he will need surgery. He said that it will probably keep popping out with trauma as the joint will be unstable. Said each person is an individual so it will depend on exactly what and where the injury is. The good news is long term he should be fine.