I once went to the doctor with knee pain in a spot close to that (but on the opposite knee) and he sent me away with (besides a prescription for anti-inflammatory drugs) a sheet of exercises for stretching and strengthening the legs. So, in addition to the above advice, you might start a regimen of stretching. It's one of those things that might not help but certainly can't hurt, and is therefore a good thing to try first before anything drastic.