I had the same ordeal in 2020-21. Went to 4 surgeons besides original and after 28 months of swelling, pain and 3 blood draws, on doctor asked if I had any allergies. I said not that I know of. He sent me for testing and found I am very allergic to Methacrylate- the stuff the cement they put the tkr in with contains!!! I immediately started taking antihistamines (Claritin generic) and within a week swelling and pain gone. I have since climbed Machu Picchu and hike 5-8 miles a day in CO mountains in the summer. Told this was very rare- but have heard of a couple other people. They do not do pre-testing for it.