I agree that doctors usually do a good job of determining what happened. The problem is that they are often at a loss to explain why something happened or what to do about it. Something about their training seems to give them tunnel vision and focuses them on solving the problem rather than preventing it. Of course, it might be the case that they have a perverse incentive to not fix the problem. In the same way that I don't know who will invent a gadget that will eliminate the need for shaving, but I'm pretty sure it won't be the people at Gilette, I don't know who will eliminate the need for Tommy John surgery, but I'd be willing to bet that it won't be Frank Jobe or James Andrews.
As an example I give you this study...
http://mednews.wustl.edu/tips/page/normal/6099.html
They explain that pitchers lose range of motion in their pitching elbows but don't seem interested in why or what to do about it.
The only person who even attempts to answer these deeper questions (but still not to my complete satisfaction) is Dr. Mike Marshall. To find out what he says about this subject, Google "mike marshall range motion pitching elbow".