How do they determine if you have osteoarthritis or rheumatoid? Have your knees affected the hip joints any?
Speaking as someone with two arthritic knees, anything that affects your gait can add to the wear and tear on your knees. When I hurt my first knee, that made me walk funny, which probably didn't do the other knee any good, then I hurt the good knee. OK, maybe I just have bad genes, but I do know when I limp, my knees hurt worse.
I think that thigh atrophy and tight calf muscle would definitely pull things out of their normal position, causing extra wear and tear. I think osteoarthritis is less of a bummer than rheumatoid, so maybe it could just be a bow on your neat single package.
I would LOVE to wrap up everything in a nice single package! I have so much going on that I totally confuse my doctors. I get confused myself, trying to figure it all out so I can make the most out of my life.