It is wonderful to see all the links to read about non-metal materials and stem cell therapy! I have always believed stem cell therapy to be so expensive? (at least on Medicare). My husband had a hip replaced over a year ago - he had a known allergy to nickel and after the replacement found out he also had an allergy to titanium!!! He is now on Dupixent, since Jan., and it is questionable whether or not that will prevent symtoms. Our allergist says she is trying to get the word out that there is a test for heavy metals that should be used when there is a question about allergies. You need to find out all you can before the replacement Knowing you already have a titanium allergy, to me, would be a red flag!!!!!!