He has access to rehabilitation facilities most people couldn't dream of. UT is 1st Class in this regard, on-field record notwithstanding.
Of course, this is where personal drive and genetics that doctors can't ascertain come in. He busted his azz to rehab himself and get healthy. Jones deserves a lot of praise for his drive, based on what Butch and this article are saying.
Butch called him the hardest worker on the team, IIRC.