17 year old joint inflamation in ellbow help!

Hi, my 17 year old son is playing basball since his age of 8.
He is in a baseballschool since last summer and now ve can‘t play any games since 4 month because of ellbow pain. He had MRI and went to Ortopedic doctors. But nobody has an solution and nobody can‘t help him. His radiohead is a bit dislocated and he has inflamation in tissues in his joint and sometimes the hurt moves down or up the arm. His dream is to pitch in a baseball college. Now with this hurts he needs help!
Has anybody recomendaciones or similar experience. Thankfull for any answers.