Hi Liz - this is a late answer but if you can get your hands on some Voltaren Emulgel, it's a topical anti-inflammatory awesome for bony joints like the knees. You can get it in Canada but not in the US.
Hi Liz! My knee gets the same when I ride usually due to to much weight, but it's still sore. I take a hot shower and use natural village muscle relaxer body wash. I also put a heating pad on to help.