BONE ANCHORING ELEMENT INCLUDING HEAD AND SHAFT WITH BONE THREAD-FREE SURFACE

摘要

PURPOSE: A bone anchoring element is provided to permit the element to be rapidly and easily inserted into a bone with less force, and prevent damages to the bone. CONSTITUTION: A bone anchoring element(1) comprises a head(2) to be connected to an external device; and a shaft(3) having a bone thread(5) formed at a predetermined portion thereof. The shaft has at least one bone thread-free surface(6) extending from a first end to a second end of the predetermined portion of the shaft along an axial direction of the shaft. A distance between the bone thread-free surface and an axial line of the shaft is smaller than a distance between a sharp end(4) of the bone thread and the axial line of the shaft.