Locking device for securing a rod-shaped element in a holding element connected to a shank

Abstract

A locking device is provided for securing a rod (100) in a receiving part (3), in particular a polyaxial bone screw, wherein the locking device has a sleeve-type element (40) with a cylindrical outer face and with an outer diameter which is dimensioned in such a way that the element (40) is displaceable between the legs (9, 10) of the receiving part (3) and wherein the element (40) has an inner thread (43) for receiving an inner screw (60) and with an outer nut (50) which can be screwed on to an outer thread (12) of the legs (9, 10) to fix the element (40). In the polyaxial bone screw the element (40) acts on a pressure element provided in the receiving part (3) to fix the position of the head (2) of the polyaxial bone screw and the inner screw (60) acts on the rod (100) to fix it. The element (40) is preferably provided with slits (47), whereby during screwing in of the inner screw (60) the element (60) splays out against the outer nut (50) and thus effectively prevents loosening or detaching.

Dependencies are inferred from the claim text.