We're not talking balky knees here. The question with Jarvis Jones is, is he going to end up paralyzed on the field, or even dead. There is no "maybe we'll get 5 or 6 years out of him first", that's horrific. It's strictly a question of "is he at a heightened risk of catastrophic injury or not?" If he is, no one should draft him. We don't need to see a player paralyzed on the field when the risk can be minimized.