Abstract: A bone cutting device for forming an undercut in bone. The device includes a rotatable body having an inner surface and outer surface. The inner surface defines an aperture. The inner and outer surfaces are disposed opposite each other and define a sidewall. The sidewall includes a recess extending from the outer surface into the aperture. A cutting arm is cantilevered to the sidewall and disposed within the recess. The cutting arm includes a flexible depression extending into the aperture. An actuating member is longitudinally slidable within the aperture such that sliding the actuating member longitudinally interfaces with the flexible depression and pushes the cutting arm radially outwardly.