I was close
Twasn't my ACL, 'tis my MCL. (Medial as opposed to anterior) The doc said it didn't look serious so it should have healed up by now on its own. He said it may not have healed yet because it's being re-exacerbated. I said, "Hmmm, maybe by going to karate twice a week? After which it always feels even more sore?" (Hey doctor, it hurts when I move my arm like this.) So he told me what any schlub on the street could have told me for 5 cents. Take a break from karate! I'm going to stop going for about two weeks, and if my knee doesn't start to improve, they'll take a closer look. But the good news is that I can still start training for the triathlon with some gentle biking because it will keep my knee moving in a nice, straight plane. So I tried, Karen, but I guess I'm not backing out after all!