@mabfp3
I was thinking the same thing. I am not allergic to metals but my surgeon likes the Smith & Nephew package (he helped design the CORI robot) which uses an oxidized zirconium material for its implants so that is what I received.

Ask (demand if necessary) detailed information about your two procedures. Every time a surgeon does a procedure he should have dictated and written an after surgery report. Mine was 2.5 pages long. If your surgeon has a patient portal, it might be there. At the end of my report it said Smith & Nephew implant but not which one (I know which one because it was a BCR procedure).

Saying you got a "top of the line" implant is nonsense. Every brand has a top of the line version. However, if you got an "oxinium" implant it is supposed to be biocompatible. But saying "top of the line" sounds to me like an attempt to obfuscate, not clarify.

Revisions are more complex than regular TKRs. Not all knee surgeons do revisions and of those that do, few are ones I would trust to do one for me.

I would be hesitant to have a surgeon go in a third time for me BUT I would rather do that than suffer.

The first thing you need to do is fire your surgeon. If you have some really good doctors that you go to (e.g., a rheumatologist, a neurologist, internist, etc. etc.), especially older ones, ask them whom they have gone to or would go to. For example, my knee surgery was delayed because my surgeon had torn his rotator cuff skateboarding and was recovering from shoulder surgery. I have a friend who needed a third shoulder surgery. So I asked my extraordinary hip/knee surgeon whom he had used and then passed that information on to my friend.

Another example. I was in my top rated rheumatologist's office when he got a phone call and apologized saying that he had to take the call because it was his wife and she was getting her hip replaced the next day. Well...of course...it was my surgeon!

Figure out what you optimally want/need and then search the web for that and you may see some scientific papers, etc. That will lead to further research.

I didn't need a revision, I needed a TKR. I was in pain and was also badly misaligned (valgus). These were my criteria and one like it (depending upon your needs) would work:
(1) subvastus or midvastus method (not relevant for a third revision but useful in determining the skill and practice of the surgeon); (2) Able and willing to do a BCR (also not directly relevant but a BCR is complex surgery so a surgeon who can semi-routinely do that is a skilled surgeon); (3) Does NOT use a tourniquet; (4) Does a "functional alignment" (I would have accepted a kinematic or inverse kinematic alignment BUT NOT a mechanical alignment); (5) Does revisions (my surgeon spends about 20% of his time doing revisions of other surgeon's work); (6) Has EXTENSIVE SUCCESSFUL EXPERIENCE DOING THE SAME EXACT PROCEDURE; (7) Has great hands; and (8) Has a great mind.

I hope you can find such a revision surgeon locally. I did and had no post surgery pain and on the 23rd post surgery day my physical therapist measure my ROM at 122. Incidentally, the same surgeon had replaced my hip about three years ago and, again, I had no post surgery pain. If you cannot find such a surgeon locally, and if you can afford it, travel if necessary to get such a surgeon.