Thank you for the information. I spoke with my doctor about it on Friday and she took X-rays of my knees, I haven't heard results yet, but the technician showed me the X-rays and I couldn't see any bone deterioration but I'm not a radiologist.
My doctor said that the replacement therapy doesn't as directly constitute the long term use of corticosteroids as for someone who produces there own and uses them for treatment of other things, this makes sense to a point, but there could still be more than the body requires that may contribute to side effects I think.
This is an interesting discussion to consider, my Mother, who was a carrier, had knee problems and had to have both replaced. So I do wonder if it is something common to ALD/AMN.