I mean this joint is jumpin'

Tomorrow I go to see the doc. For ages and ages (ever since I had my foot operated on) my knees have been giving me gyp, which rather put paid to my plans to run a marathon before I'm 50, but now my hands started playing up too. It started when we were having to test PS2 games at work (yes, that really is work) and I found the control wotsit terribly awkward to use. Twiddling the sticky bits (not sticky as in adhesive, but as in like sticks) with my thumbs was especially painful. Over the weekend I found it well-nigh impossible to even carry a plate, because my thumb joints hurt too much to be able to stop the plate tipping. So I'm going to see if he can tell me whether it's the onset of arthritis or osteoporosis. Neither's out of the question.