The metal medical devices, are changed over time. So the earlier surgery could have used a different alloy.

What we see here from others who have had procedures done, MRIs can be problematic with that contrast medium ragtop mentions, and endoscopes are alarmingly increasingly becoming contaminated and not adequately sterilized so patients may be
infected with "who knows what" .

I had a new crown made for a molar last Jan. The temp my dentist put on was made of steel/nickel. One night some salt or something reacted to it, and the gold crowns above, and one mercury silver... and I had a two beat throb...in that tooth, followed by what I can only describe as an electrical jolt that went to my neck and down into my chest affecting my heart beat. I almost lost consciousness, and it took about 5 minutes for my heart to stop racing. It was an awful experience, so I looked it up...

http://toothbody.com/is-there-a-battery-in-your-mouth/

I was using a salt substitute (Morton), which has fumaric acid in it (why, I had no idea)...I can't use salt, so at dinner I use a small amount of this product. My dentist has never had anyone report something like this either. But it happened to me.

Weird things happen when metal gets into the body. I switched to NOW brand salt substitute...it does not have acids in it. But it was a painful frightening lesson to learn for me!

Try a search on Google... I found this one by doing
metal implant reactions:
http://www.arthritis.org/living-with...-allergies.php

I saw many other sites with discussions.

Some people will react to foreign bodies in their bodies, more so than others. Everyone is different.

Do see that your B12 is above 400pg/ml, and your Vit D at least at 50, and that you use some form of magnesium supplement, either the new lotion, or a good oral form (not oxide type), and see if you feel any difference.