I really think the "injury prone" label ist hrown around here about players, especially those that suffer broken bones etc... playing in the NFL. When I think of injury prone I think of a player that has a debilitative injury that gets worse with time and has little prospect of improvement. Sebastian Vollmer is far closer to injury prone than Aaron Hernadez. He has back problems which have a higher than average chance of re-occurring in the future.
If I break my collar bone (Amendola) and miss time I am less injury prone than someone whom has had knee injuries during their career and are getting up in years (Welker.) Fans seem to hold a vendetta against any player that has a freak injury. I doubt that franchise administrations view players that have correctable injuries in the same way.
When we look at the future injury prospects of a player we have to consider just that the FUTURE likelihood of injury not the past performance. Broken bones are not a disease. A shoulder injury can linger example I can think of would be past patriot CB Duane Starks recovered from his shoulder injury (torn tendons.) We have no information here that would lend any credence to a theory that Aaron has any sort of injury like that.
Injuries are rarely positive, they happen, it is a violent sport played at the highest level with bigger stronger faster athletes creating more forceful collisions. Any player can go down on any play if their number is up. Only in special circumstances does it mean that a player will never recover or that it will be a career threatening injury.