At the hardened-off age of 69 I had total knee replacement surgery one at a time. This was major surgery each time, followed by long slow painful difficult recovery. Well worth it because each time, something that was worn out and could never work again now works. Not quite to the original specs, but this only means pay attention during rehab that you know the new spec limits and have learned the muscular targets to stay within them.

I can't help but think that gender reassignment surgery only occurs when it is groomed. I think it is criminal to groom a child to consent to such a thing. And this is a much worse kind of surgery, for it turns what works into what doesn't work. It should fall under the crime of maiming. Good practice is to let a child be a child who studies much so they can make intelligent decisions as adults.