The surgeon used a semi-cylindrical bone saw, in a reciporcating rotary tool, to cut and repositon one of the bones (above or below the joint, I forget..) in order to redistribute the loads normally carried by the ACL (surgeon said it was Crainial Cruciate Ligament).
A reciprocating rotary saw? A Sawzall with a wheel? They just drilled holes in my femur and fibula and stuck a donor in there. It was painfull. More than the injury. (Aluragraph). Autograph is a bodies own tendons borrowed. Alluragraph is a donor ( a deceased organ donor).