Bone anchoring device
A bone anchoring device includes an anchoring element having a shank to be anchored in a bone or a vertebra and a head, a connection element for connecting at least two anchoring elements, a receiving part having a first end receiving the head, wherein the head is pivotable in the receiving part, and a second end comprising a recess for receiving the connection element, a first pressure element which exerts pressure on the head to lock the head in the receiving part, and a second pressure element which exerts pressure on the connection element to press the connection element against the first pressure element. The contour of the surface of at least the first pressure element or the second pressure element facing the connection element deviates from the contour of the surface of the connection element.
1. A bone anchoring device comprising:
an anchoring element to be anchored to a bone or a vertebra and having a head;
a connection element;
a receiving part having a first end for receiving the head of the anchoring element, wherein the head is pivotable in the receiving part, and a second end having a recess for receiving the connection element;
a first pressure element configured to exert pressure on the head to lock the head in the receiving part; and
a second pressure element configured to exert pressure on the connection element to press the connection element against the first pressure element, wherein the second pressure element is configured to apply pressure directly to the first pressure element;
wherein when the connection element, the first pressure element, and the second pressure element are in the receiving part, a contour of a surface of at least the first pressure element or the second pressure element facing the connection element deviates from a contour of a surface of the connection element;
wherein the first pressure element is configured to directly contact the head of the anchoring element when the bone anchoring device is in an assembled state; and
wherein the connection element is made of an elastic material.
2. The bone anchoring device of claim 1 , wherein the connection element is a rod.
3. The bone anchoring device of claim 1 , wherein contours of the surfaces of the first and the second pressure elements facing the connection element each deviate from the contour of the surface of the connection element.
4. The bone anchoring device of claim 1 , wherein the deviation of the contour of the surface of at least the first pressure element or the second pressure element comprises any one of at least a projection or at least a recess.
5. The bone anchoring device of claim 4 , wherein volumes of the projections and recesses are substantially similar to each other.
6. The bone anchoring device of claim 1 , wherein the deviation of the contour of the surface of at least the first pressure element or the second pressure element comprises any one of at least a rib structure or at least a pin structure.
7. The bone anchoring device of claim 1 , wherein the deviation of the contour of the first pressure element or the second pressure element extends in a direction perpendicular to a longitudinal direction of the connection element.
8. The bone anchoring device of claim 1 , wherein a surface of the first pressure element facing the connection element extends above the recess of the receiving part when the bone anchoring device is in an assembled and tightened state.
9. The bone anchoring device of claim 1 , wherein the contours of the surfaces of the first pressure element and the second pressure element facing the connection element remain constant prior to and after the bone anchoring device is in an assembled and tightened state.