Brother, Get to the VA as fast as you can, call your local goverment office and ask for the number to the local VA rep. You have service related bone and joint degeneration and are probably entitled to Disability and FEDERAL HEALTH care from the VA. Just wondering what was your MOS? No good ortho surgery is cheap, but it may not matter if you can get into VA. As a for instance, my father in law was a drafted Army mortarman in vietnam, only did his required draft service.  30 years latter his knees started failing him.  The VA has offered to do a complete double knee replacement and he gets about 1200 a month in disability.  DO NOT feel guilty about asking for benefits you earned with your sweat and hard work.  I hope you get the help you need.  Semper Fi Brother.  Here is to a speedy recovery, but if the path is long heres to the heart to finish.  if for some reason they tell you you will not be a runner, make sure you get a second opinion from a real sports medicine guy.  If that fails, the bike and swim might just be your permanent fallback, but there are a ton of non-run events out there.