My wife  [80 yr old, & married to me for over 50 years] - has, over many years -  had several full joint replacements.
2 knees, 1 hip, and most recently  1 full shoulder.
She complains, from time to time, of pain seemingly from the joint area. 
All the replacements are titanium metal, and she has hit on the idea that she may be allergiic to titanium.
So  - questions to the huge resource that is NAT!
1. Does anyone with titanium joint replacement [s] have any pain eminating from the replaced joint area?
2. Any other material used for replacements, and the reasons given for using something other than titanium?

My personal experience:-   
Full right hip replacement [titanium] coming up 10 years ago - no problems.
At the most recent check up I was told there is no sign of any wear, so it will well and truly see me out!  I am 80 yrs old too.