I had a breast biopsy where they left in the metal clip. I know I have a nickel but the clip was titanium. My breast was so itchy tho it looked fine. I was driving me crazy as it became painful. I went back, he was a good dr, really great "womens cancer surgeon." (Gratefully the biopsy was negative) but he was going to Ukraine to do volunteer cancer surgery on women. He had a hard time believing it was a nickel allergy, but I did research. Titanium can contain anywhere between 5 to 30 % nickel. I had trouble finding similar cases but did find a few. The cases I saw all had to wait months and months before the surgeon would agree to remove it.

Because he was leaving and has a rule to not do any surgeries for 10 days before he leaves, tho at first it was a repeat stereotactic biopsy to try to get it out the way it went in and if they couldn't get it, I would need actual surgery. Things were so bad and would be for 6 weeks, I asked my pcp to order low dose Prednisone. It seems over the top but even living in chronuc pain (crps) this was intolerable. By the time he was able to remove it, the tissue with it that was sent showed mastitis. Painful. He had never seen it before in 30+ years of breast biopsies, but has seen it now.

Previously I had a TKR. I didn't even think to mention the allergy because my only problem that point were cheap earrings that would turn my lobe bright red and painful. But here is what I discovered so its a thing even if Drs haven't heard of t. (I'm an RN, this was very real.)

I saw a preop patient checking out with a thing taped to her arm. She was saying it was to test gor a nickel allergy as many if the knees contain large amounts of nickel. That's when I thought to mention it. It was in my allergy list. I told the surgeon 5 days before surgery and he needed to order a whole different knee with less to no nickel.
But, if they had taped that to my arm, it would not have read positive and now I know I would have had to have it removed.

This is when I realized for me, internal allergic reaction and external can be different. I was very allergic to cheap earrings as they were loaded with nickel. But the back of my watch didn't affect my skin at all. My sister has such a nickel allergy thst she can not wear a watch. The plastic piece near your nose on her sunglasses came off and she didn't know. She was on vacation and ended up in the ER with a big hole in her face.

So placing their piece of nickel on my arm could have ended badly. Replacing a knee replacement is a very specialized surgery maybe a whole different surgeon. If you are a person with a piercing, try a very cheap earring. In hours I have to take it out. Some pain but mostly unscratchable itching inside my body. Hope this helps. Don't let your dr convince you that there is no nickel inside titanium. There is.
Sorry this was long. (Btw, my breast still Itches bad sometimes. The mastitis was never treated.