Surgical procedure of knee joint

A surgical procedure of preparing bone holes to dispose an implanted tendon to a femur when performing reconstruction of a ligament in a knee joint, includes: forming a first bone hole in the femur; and applying ultrasonic vibration from a treatment portion of an ultrasonic treatment instrument to the femur, thereby cutting and expanding the first bone hole from the inside of the knee joint to the first bone hole of the femur along a predetermined depth, and forming a second bone hole having a polygonal shape, an approximately polygonal shape, an elliptical shape or an approximately elliptical shape to receive the implanted tendon.