Can sagging elbow skin be surgically corrected?

It can,albeit it's not an easy procedure. The skin over the elbows (in most people) is thin and not very stretchy. Also the area that forms the callous pad is quite well-defiined and must be placed properly. Surgeries that are performed over an areas that invovles many different textures of skin are inherently difficult to get right. That said, if you have the patience and the money, you can get it done and even done well.