Unlike in a healthy shoulder, where the humerus ends in a ball shape and fits into the shoulder blade to form a shoulder, in reverse shoulder replacement surgery the anatomy is reversed.
True to form, when he finally begins the shave, the blade slides across the surface of my face, cutting the whiskers as if they were gently heated butter.
If you reside in the US, you'll need to fill out a form, send off pictures of your keys, and you'll be provided with blank "Blade" inserts for making compatible copies.