I had my right knee replaced in Oct 2000. I'm only 42 but had a serious accident breaking my knee into three pieces which caused osteoarthritis compounded by an infection which destroyed the remaining cartilage. I was walking the day after surgury. It was painful but necessary. The first two weeks are very difficult but you have to work through the pain with your physical therapists. Use the CPM, continuous passive motion machine to keep your range of motion. This hurts as well but gets better. By three weeks I was walking realitively well. By 6 weeks I was doing yard work, swinging a pick ax and using a shovel. At 4 1/2 months I went snow skiing. Everyone is different, if you are motivated and can handle pain initially you will do well. You just have to believe that the first 2-3 weeks will be the worst and it does get better. My range of motion is 120 degrees and the grinding in my knee is gone. The harder you work the sooner you get better. Good luck.