A surgical instrument includes a housing having a shaft extending therefrom. The housing includes a nose having a neck and a base that defines a diameter greater than that of the neck. A rotation knob has a distal end defining a first aperture and a proximal end defining a second aperture, the apertures cooperating to define a lumen extending through the rotation knob that is configured to receive the shaft. The first aperture defines a diameter that generally approximates a diameter of the shaft. The rotation knob is transitionable between an at-rest position and a flexed position. In the flexed position, the second aperture is expanded to permit passage of the base of the nose into an interior of the rotation knob. In the at-rest position, the second aperture generally approximates the diameter of the neck to rotatably engage the rotation knob about the nose with the shaft extending therethrough.
