I've had both of mine replaced. The left one 2.5 years ago, and it was good enough for a Colorado elk hunt last year where I had to pack the elk out on a backframe (three trips up the mountain). I had the right one done earlier this year and it's not 100% yet but getting there. I can walk without pain. I can kneel but like others said, that's a little uncomfortable unless I have a little padding. I can even run a short distance if I need to, but don't make a habit of it. I can walk as far as I want to, pain free. I hit rehab hard. If they said do 30 reps I did 40. I went to the gym on the therapy off-days and worked it some more. I know it doesn't work the same for everyone, but it was the answer for me. I'm 59, btw.