I had tkr right knee 1 year ago. I have only gotten 90 degrees of flex and am still in bad enough pain to be on fentenal patch. The Dr at pain clinic says it's caused by friction of kneecap to metal joint due to adheaions. He mentioned I could get kneecap removed a piece of metal attached to bottom then havee it reattached. Has this happened to anyone else? If so does it help and how bad is pain and recovery?