Wow. This might be the backbreaker here.
That looks extremely gruesome. He's still extremely young, but unlike Shaun Livingston's case, as a big man he takes more pounding in rebounding, establishing post position, etc. If and when he recovers, I think he'll be a shadow of what he is...right now. I don't think he's the type who will develop a finesse game/develop a jumper either to offset some of the difficulties. Just an unfortunate case--I think it's nearly a 0% chance, now, that he will reach that extremely lofty potential he once held.