My right knee was x-rayed and examined by the PA (who is also a sports trainer). The verdict was that I had a strained quad. Probably when I slid on a snow covered rock while dropping a couple of trees in the yard back in early March. The good news was two fold: 1) no damage to the knee joint, and 2) the strain seemed to be in the muscle not tendon/ligaments. With more blood flow in the muscle, there's quicker healing.
I was told to stay off my feet, avoid stairs and take some prescription anti-inflammatory. Double doses a day for the next two weeks and then single dose per day for another two weeks. If I must walk and or stand for lengthy periods, then I should ice the knee immediately afterwards to reduce inflammation. If, after a month, there is no improvement, I go back to the orthopedist. If things get better, then I see them in July for my knees' one year anniversary.