i had ankle fusion on august 29...when he did what he thought would be routine...and put the screws in my ankle..it was like a sponge...he said,,so had to do extra screws/pins into my heel.
i too wonder about the osteoporosis factor..cause my other bones...tibia, heel, etc were fine, he said. plus, i have had two bdt, and they were both fine....on my spine and my hip.
so i guess you can get it in any bone, if it's been damaged. i broke my ankle when i was 20yo.(56now)...had it xrayed many times up til the surgery in august...