I am nearly 6 years post left TKR. I was bone on bone and wearing grooves. I waited way to long to see an orthopede. My surgeon is well regarded locally, and had no issue at my age, then 47. His biggest suggestion of what I shouldn't do was snow skiing... Running, as long as I had no pain was allowed. I am the oddball, at 7 months I jumped off an ATV just to see how it felt... Felt fine. My suggestions beyond finding a surgeon. Work to strengthen the quad muscles, do a lot of standing from knees on the ground, that will be important later. STRETCH the other leg too. I spent some time after surgery recovering from a MCL injury to the other leg. So work them together. DO all your post surgery therapy. Even the work they give you to do at home. I have excellent Range of Motion. Nearly 6 years after replacement. 146* and the knee is designed for 150*. Bottom line, is, the knee no longer holds me back. Plenty of other things have... But not the knee...