Carole, sports medicine doctors are usually the best and most up to date, that's a good choice. I also suffer from severe arthritis (it's all over, and it's psoriatic, which most people aren't familiar with). I have not had knee replacement, but did have tendon replacement surgery in my leg; the posterior tibial tendon, which is the major work horse tendon of the lower leg. I went to our sports medicine facility here (where the RAVENS go - you may have heard of them!) and they did a wonderful job. Six weeks out of commission and lots of therapy, but it all was worth it!

I have also known others with knee replacements; they're all much better than when they started (my father is one-he has a titanium knee, and is about to get the other one done). As long as she's with a good doctor, she should be much the better for it. Good Luck!