I had a total knee replacement Feb 28, 2013 and am now 3 months out. Got off to a rough start, because I developed a deep-vein thrombosis in my calf soon after surgery. So I spent a week and a half flat on my back with my leg elevated. I began using a stationary bike immediately after that. At first, I couldn't make a complete revolution of the pedals. Nonetheless, I used the bike to stretch the knee, increasing flexion. That worked wonders. I began riding outdoors by about week 6. By about week 8, I was riding to work and back, 3 miles each way. The knee feels solid, and I'm not worried about hurting it. Trouble is, there is still a lot of swelling. I suspect I may be riding *too* much, so I plan to cut back.