I'm pretty sure he tore the right ACL at Penn State and the left one here, unless you are talking about some other injury.
He's missed time with a dislocated wrist, neck strain, and two ACL injuries the last one with a mild meniscal injury. He tore a ACL in college as well although I can't tell is one of those is a total of two or a total of three knee injuries.
So he's missed some time.
I've gone into detail the mechanisms of injury for these and they are plain physics. There is no 'propensity' for these injuries to be weak connective tissue in the very vast human population playing NFL football.
If you wish to say he's snakebit then I'll agree it appears that way.
There is no evidence I know of that suggests he has subpar repairs of his injuries. And he does play at perhaps the worst injury plagued position in the NFL.
Did we have a player not dinged up some last year at LBer? Wilber?? Hitchens??