ROTATIONALLY RATCHETING BONE SCREW

摘要

This invention is a rotationally ratchet bone screw (10) including a body (20) having a distal end (24) formed with an engagement tip (22) for engaging bone tissue, and a shaft (26) formed with a unidirectional stop (30). The bone screw (10) further includes a fastening element (40) formed with an opening (60) complementally configured to receive the shaft (26) responsive to relative rotation between the shaft (26), and fastening element (40) to axially advance along the shaft (26). The fastening element (40) includes a rotationally sensitive ratchet element (70) to be cooperative with the stop (30) to inhibit relative counter-rotation between the shaft (26), and the fastening element (40).