My father had one in his early 80s, totally unaware he was slightly allergic to transition metals (nickel, mainly - I've inherited it which is why I know)
The incision never totally healed: he ended up with one leg 4" shorter than the other and recurrent bouts of eczema / dermatitis which were not satisfactorily treated, though he was his worst enemy in this respect.

Go for it: but if you think you might have this (or any) sort of allergy, shout about it loudly beforehand. There are alternative prostheses avoiding the critical materials, but the medics won't use them (UK - they're more expensive) unless a fuss is made.

My dad was still driving, aged 88, 3 weeks before his death (of something totally unrelated), although he couldn't walk far it did improve his quality of life.

Paws