Patent ID: 8123784

Claim:
An anchoring element for use in spinal or bone surgery; said anchoring element comprising: a shaft for anchoring to a vertebra or a bone section; a rod for connecting to the shaft, the rod having a pre-determined diameter (D) and an outer surface; a receiving part that is structured and arranged to connect the rod to the shaft, the receiving part having a longitudinal axis and comprising a U-shaped recess forming a channel for the reception of the rod and two legs having free ends, the legs comprising a first internal thread, the legs further providing an exterior end surface of the receiving part; and a securing element comprising a screw member having a first external thread that engages and cooperates with the first internal thread to result in contact between the securing element and the rod to fix the rod in its position in the channel of the receiving part; wherein, when the rod is located in the channel, a first distance from the exterior end surface of the receiving part to a closest portion of the outer surface of the rod in an axial direction is a pre-determined distance (A), the first internal thread extending from a first location at or adjacent the exterior end surface of the receiving part to a second location that is a second distance from the exterior end surface that is smaller than or equal to the pre-determined distance (A); and wherein the receiving part further comprising an undercut on an inner surface of the legs adjacent to the first internal thread, the undercut extends in a circumferential direction and the first internal thread extending to the undercut, the undercut having an edge farthest away from the first internal thread, the edge being located at a third distance (B) from the exterior end surface, the distance (B) being larger than the predetermined distance (A); wherein the first external thread of the securing element is movable into the undercut; wherein an entire length of the securing element in the axial direction is equal to or less than the predetermined distance (A).