I didn't know I was allergic to nickel. I wish they would give everyone an allergy test before TKR.

I had allergy testing at National Jewish in Denver, Colorado. Dr. Karin Pacheco. She tested for various metals and bone cement allergies.
Definitely worthwhile.

Allergy Testing- My orthopedist also said it was highly unlikely to be allergic to TKR components and I if I still wanted the test I had to pay out of pocket $600.00 up front for the blood testing for metals and bone cement used in TKR. I appealed to Medicare showing my history of allergies to many elements and these patch tests costing about $1,500 each time were paid for by Medicare. Still Medicare denied coverage of testing for TKR. The best thing I ever did for myself was pay personally for this testing before my scheduled surgery. I was allergic to 5 metals, ironically not the bone cement. I was not allergic to titanium, but it was explained to me that even titanium has many other trace metals in it which I was allergic to. I have allergies to several adhesives which are rubber or acrylic based, but not bone cement. I canceled surgery.
Even the ceramic coated implants fail to protect over time because of wear of the coating and if one has a bone cement allergy there is no benefit from a coated implant.

Side note, I know this is like playing with fire but I got the Zilretta, a time released, pelletized steroid injection in both knees 2 months ago.
Unbelieve. I still have zero pain walking up and down stairs, also if on the ground I still feel the need to roll to the front and press up with my arms for strength and balance, yet my knees aren't making me scream in pain, they feel normal, like a kid again. Medicare pays for this injection. Evidently it will do this 4 times a year. Steroids all come with side effects in the end so will put this off and perhaps treat myself to it once a year.