Sure Elbows cut, especially IF you throw them that way ( which most do) but they can also smash ( in karate they fall under the category of "ate-waza" smashing techniques), anyone that has ever sunk in a hard elbow to the body knows its effects.
Because of the tendency for the elbow to be "overly" circular and aimed at the face, it tends to get more cuts than KO's and when it does, people tend to view it as a "forearm smash" as opposed to an elbow.
We all remember Pat Smith destroying "Ninja Bob" in UFC 2 ( I think it was 2) with elbows from the mount.
And elbow KO's happen frequently in MT.
Psalms 144:1
Praise be my Lord my Rock,
He trains my hands for war, my fingers for battle !