Re: Osteocondritis Dissecans Pain (Non-surgical)
Kathryn, I was diagnosed with an OCD lesion as a teenager as well. My understanding, OCD is when the blood supply is compromised, and the bone starts to die/soften/dry up (i.e., "dessicans - dessicate, dry out"). I have been through several procedures related to it. I had several ups and downs along the way, so I feel your frustration.
I did not think OCD could heal on its own, they went in surgically to fix mine (by putting "sponge-like" pins through the area, to draw blood in). X-rays showed lines of bone forming, and ultimately, my area almost completely filled in. However, my injury came with a cartilage tear as well, and that's what I've been dealing with. Your inability to stretch your quad or walk stairs, reeks to me of cartilage damage. I would be sure your doctor has examined that aspect thoroughly.
As for your prognosis, I'm going to have good news and bad news. The bad news is, "impact" sports are going to be hell on you. For me, it was basketball: a hard floor, a lot of sudden stop/start/cuts...it will kill you. I had to eventually give it up, even on a recreational basis, it's just too much. Here's good news: I believe you can help yourself a lot with PROPER leg work. Work your quads and entire core/posterior chain, but do it properly. In a lot of Crossfit, you'll hear, "weight on your heels" - getting your weight on your toes will hurt your knees. PROPER strengthening on your legs will help tremendously.
Overall, I think your issue is more cartilage-related. Get that sorted out. When that's cleared, see what the prognosis is for your OCD lesion filling in, which may just be more rest? After that, you may need to tweak your permissible activities, I know, and I'm sorry if that means giving up something you love, but I think you can definitely still be active via other sports, and your knee will hold up well.