I had TKRs on both knees this year and everything went well. I got in shape well before surgery, and followed all PT instructions rigorously.

Even so, I get pain in my kneecaps when I get up from a cushioned couch or chair - basically my knees are above my butt. The pain is short and not all that bad. It's only been a few months, so I'll continue to strengthen my quads and hopefully next year it will be better. Also, I'll use my arms more and whenever I can when standing up.