The Gelpi Odd Leg consists of two asymmetrical arms, hinged in the center, which separate when the handles are closed and are held in position by the rack. The ends of the arms have small atraumatic hooks that engage the incision line to maintain good exposure to the surgical field. Gelpi Odd Leg is used in spinal surgery, with the shorter arm attaching to the spinal cord and the long arm retracting the long muscle of the back.