I too had knee replacement and found out 5 years later I am allergic to cement. My knee could hardly bend. I have auto immune and cannot take medicines like blood pressure and antibiotics without horrible pain on side of implant and in implant. No doctor has heard of such a reaction. The allergist thought a special diet might reduce some of the inflammation I am having. This has been 10 years of pain with joint and orthos say it is sound and can’t understand my pain. It is so discouraging. I am told only cement on revisions. I wish I could find a cementless doctor. I am in Boston and have been to every hospital with no success. I was told cement is used as a binder in some medicines. I was lucky as I did not need medicines till now and they are life saving ones, but the pain is awful. The pain goes away if I stop medicines. My auto immune causes neuropathy that pulls on my implant and makes it feel like arthritis. I wear a brace to take away the pain. Your situation sounds like mine.