Eyeballs? Do it in a couple different languages and your hip might be the next Rosetta stone.
There was a 70s movie, and I assume a novel, about a spy with amnesia who had a swiss account number engraved onto such a plate. But I cannot seem to google it atm.
Bourne takes from so many spy stories that i doubt it possible to mention one without seeing it somehow mirrored in Bourne.
------------
For below (as I've hit the 3posts/hour limit) maybe I was thinking of bourne, but only if he had a plate with the number on a bone. The thing I remember was that the number only became apparent at the hospital during an x-ray, after the accident that caused the amnesia.
Are you sure it wasn't that one?