I also agree with the direction this thread has taken. Don't buy into the long term prognosis of any, or at least any one doctor. They are full of it. The acquired knowledge they get on long term stuff is only so good, and often it isn't good at all. And the vast majority of doctors haven't been actually practicing the profession long enough as a specialist to have their own long term experiences. Doctors and the medical profession have only three tools in the tool kit. Cut it, drug it, or therapy it. That is their expertise, and those are the things they monitor for outcomes. Things like eat better, exercise more, and get some sleep are not monitored for outcomes because you don't typically go back to the doctor for them. I have nursed my screwy knee back to full health. Most cartilage problems are traced to impact damage, or overloading (over weight). Your joints can be conditioned to take small impacts over and over (running), but even that will kill them if you don't slowly condition them first. There is no way I know of to condition for big impacts, but maybe people who jump a lot know something I don't. Once damaged, joints take forever to heal compared to many other injuries. Sometimes years. I could barely walk up a flight of stairs 10 years ago. I can sprint up them now, pain free. Like the other stories already, I ruptured an Achilles tendon in December 2003. I was told I would never run again. I ran a 1/2 marathon in 2005. Personally, if I was in your shoes I would do some research and figure out how to get healthy. I'm going to guess the knee comes around if you do. One last thing. Riding a bike may help. The limited range of motion and the limited impact can let your knee heal while allowing for vigorous exercise. A rowing machine is another way to limit loading and impact while exercising. The problem with rowing machines is that they are indoors.