I've known two people who've had knees replaced. One had a double done, but she was not active prior to the surgery and wasn't active after either. I never saw her do any physical therapy and she seemed just as bad as before even after recovering. The second was very active before his single knee replacement, and was dedicated to his physical therapy and moving as soon as possible after the surgery. His recovery was so fast it seemed that it flew. Hope this helps.
Meat Loaf, the singer had double knee surgery Nov 19, 2012. I've been interested in the recovery time and have been watching his progress on his FaceBook page. Kind of wondering how long it will take. Have heard from some people that they were up that day with single knee replacement, but don't think he is up that fast. Must be hell with two knees. Anyone have any expereince to share?