What a long thread! I have not logged on in so long, I see the user interface is new and different (and even better). I am posting on this thread because I have a new issue, have tried to read in library and threads to learn about it - and found similar issues in this thread. Now, about 8 months after my second TKR (and starting to feel well), I got "crepitus" (I learned the term from threads) in my knee. I can walk (3-4 miles), exercise at the gym (20-25 minutes 3 times a week), go up and down stairs (without holding on) without this issue bothering me. However, now when I stand from a sitting position, my knee makes a loud noise - seems to be located front center - and hurts. I have good flexion and extension. I have been able to stand with no issue until now (3 sets of 15 sitting to standing). I starting putting ice on my knee again after walking again - no help. What could this be? I should be getting better, not worse, right? What should I do? - more exercise? less? I am getting very worried that something in my new knee has gone wrong. Is it scar tissue? If so, what do I do about it?