Patent ID: 8568458

Claim:
A bone anchoring device comprising an anchoring element comprising a shank to be anchored in a bone or a vertebrae; a connection element having a longitudinal axis for connecting at least two anchoring elements, the connection element being made of an elastic material; a receiving part being connected to the shank for receiving the connection element and for connecting the connection element to the shank; a seat for the connection element, the seat being provided in the receiving part; a one piece monolithic locking element being rotatably engageable with the receiving part for fixation of the connection element in the seat; wherein at least a portion of the connection element that is to be received in the seat has a constant cross-section along the longitudinal axis and wherein the locking element has an engagement structure that is configured to contact the portion of the connection element when the portion of the connection element is seated in the seat and the locking element is rotatably engaged with the receiving part, and wherein when the portion of the connection element is fixed in the seat upon tightening of the locking element, the elastic material is configured to flow for a form-fit connection between the connection element and the engagement structure of the locking element; wherein the seat comprises an engagement structure that is configured to contact the portion of the connection element when the portion of the connection element is seated in the seat and the locking element is rotatably engaged with the receiving part; wherein the engagement structure of the seat comprises an elongate projection which length extends in a direction transverse to the longitudinal axis of the connection element; wherein the receiving part has a substantially U-shaped recess forming two open legs with an inner thread provided on the legs and wherein the locking element is an inner screw to be screwed-in between the legs; wherein the engagement structure of the locking element is a ring-shaped projection; and, wherein a diameter of the ring-shaped projection equals a distance between two elongate projections of the seat.