Hi. I have bilateral patellofemoral knee replacements and when I am walking, during extention of my right leg, I feel a 'clunk' and hear at least 5 or 6 loud clicks and have a burning sensation with each step. If I am only taking a few steps it doesn't hurt too bad, but when it is farther than that, the pain becomes intollerable. I have been back to my OS for the problem (also with dislocations despite the replacements) but he claims there is nothing wrong from the x-ray pictures. I am very frustrated as I feel there is something going on. My original OS moved to another state, and I am seeing another in the same office who also specializes in knee replacements, but I just don't feel he is taking me seriously. I cannot change doctors until next May when the insurance policy is renewed. Has anyone else experienced the 'clunking?' Any help would be greatly appreciated. Thank you!