Ah... my problem was tendonitis, too. Nasty stuff. You don't realize how much you use your knee until it starts hurting. But on the positive side, a steady regimen of Advil did help, once enough of it built up in my system. If you are able to pamper your knee for a while it should heal much more quickly. (I also developed a method of walking up and down stairs one stair at a time, not bending the sore knee, for several days. Felt like an idiot but I think not putting stress on it helped.)