I didn't mean to alarm anyone or cause any fear/panic. I was thinking aloud, as folks often do here. There are a zillion possibilities for post-operative pain -- I think the most likely being nerve damage that was there prior to any surgery.
I do not think your (or anyone's) doctor kept anything from them. This may be news to most surgeons as well. They go on the best information they have or can get. Besides, at this point in time, I know of nothing
better than titanium for this purpose.
It's also possible that this phenomenon happens in only a small number of people due to some sensitivity, genetic difference, contamination of the hardware.... Infections can start many ways, and may just use the titanium as a path of least resistance - like lightning. I can't even figure out WHY infection would attack or effect titanium in this way!
I don't have any solid answers. I'm just going on the same information as you, that makes me think... "Hmmm... I wonder?"

Like I said, it deserves study, but no-one should convince themselves they have an infection festering inside them from titanium implants; it's not logical or warranted at this point.
Concerns should be addressed to doctors/surgeons; not fueled by some guy on the internet musing aloud.
Doc