osteoarthritis
"My poor left knee was just ruined, to the point that I had to stay off of it for two weeks, then hobble to the Doctor's office on crutches. Osteoarthritis, the bane of people over 60. I got a shot in the knee (just a tiny sting for a few seconds). This has been like a miracle. I'm not ready to take up tap dancing, but 90% of the pain was gone by the next day.  Its just been wonderful, and I'm SO glad I went to the doctor, instead of being stubborn and refusing to go."