UK-Elephant has had a torn ACL. Skiing accident. Really painful at first, very hard to get back to the car from out in the hills. Was in a brace for the first weeks -- I no longer remember how many, but maybe she does. Once the swelling was down she was sent for physical therapy to rebuild the muscles before surgery. Then she just never did the surgery. She was a figure skater back then and that was her landing-side knee for jumps. Figure skating gives you enormously strong leg muscles and those seem to have stabilized her knee enough, although some activities can be painful I think. Not that that stops her.