Is there actually plastic involved, not to sound stupid.
Basically it's called plastic surgery because of the Greek word plastikos which means to mold or shape.
You are moulded a plastic part of your body fitted in with sugary
In cosmetic surgery they don't use plastic but it is occasionally used in reconstructive surgery. I once worked with a guy who's face was half plastic including one eye and one ear. He dealt with the handicap very well and led a very productive life. In reconstructive surgery that's sometimes the only option available.