Ah, sorry to hear about your knee problems. I have torn multiple ligaments and cartilage in both knees, so I have some idea about the pain and continuous problems injuries can have on knees. I've had surgery on one knee, and it still isn't perfect. But that is one thing they advised me to do as well: the best thing you can do is strengthen the muscles around it. I agree though...it is not a very satisfactory "remedy". It would be nice if they could just up and fix these issues permanently.
I am sorry, though. Hope you can figure something out. If you want, I can look up some rehabilitation workouts they told me to do, if you think it would help. They focus on the knees especially, so maybe it could do something.