You're not the first one to experience this. I have a friend (early 70s) who had her knees replaced. Over a year later, she is still experiencing pain. Like you, the docs aren't sure why. My buddy who had knees and a hip replaced, said the pain from the hip replacement was the worst of the two and lasted quite a long period of time. Possibly six monthe or more. It finally abated and he's pain-free now. How long has it been since your knee replacement. Perhaps you'll just have to play the waiting game.

After awhile, except for the more routine ailments, one begins to realize how little they do know or can do for the patient.