An intervertebral prosthesis includes: a body including first and second spaced apart major surfaces defining a longitudinal axis extending substantially normal to said surfaces and at least anterior and posterior sidewalls extending therebetween, the first and second major surfaces for engaging endplates of first and second vertebral bones of a spine; an aperture extending from within the body, transversely to the longitudinal axis, and opening at a major surface; an anchoring element disposed within the aperture and including a threaded shaft; and a gear disposed adjacent to and in meshed, threaded communication with the threaded shaft of the anchoring element such that rotation of the gear causes rotation of the anchoring element, and a driving rotational force on the gear causes the anchoring element to rotate, deploy from the body, and thread into a vertebral bone transverse to the longitudinal axis of the body.