In the US, if possible, my heart valve will be cut out of my cadaver and sent back to the manufacturer for analysis. The devices from my body, that have been replaced over time, were tested until failure. The FDA is very interested in performance metrics of implanted devices. The materials are not recycled in the US afaik.

Googling would answer your questions.

Pacemakers are removed carefully, especially if they include RTGs.

http://large.stanford.edu/courses/2015/ph241/degraw2/

Prosthetic implants are typically not removed.

https://www.bbc.com/future/article/20140311-body-parts-that-...

I wonder if they could be recycled? Not joking. Those hip replacement parts are incredibly expensive; I'm sure there are folks who are in need and could use a cheaper option.

I was told by an elderly foreign gentleman that he made his living by removing such things from bodies before burial or cremation. He said that the metals in teeth were most of his business.

Seems it would be easy to remove non-compostable materials first.

probably pales in comparison to other waste