Had some knee surgery myself a number of years ago but not a replacement. One of my co-workers had a knee replacement last year and has recovered very well. The doctor suggested he put a stationary bike in his office and spend as much time on it as possible as part of his physical therapy. He was using a cane for a few months but now you would never know he had a bum knee. Mine's screwed up again now and I'm seeing the orthopedic surgeon next week, I'm hoping he says it's nothing serious.