Coupling device for coupling a rod to a bone anchoring element and method of manufacturing the same

1. A coupling device for coupling a rod to a bone anchoring element, the coupling device comprising:

a receiving part having a first end and a second end below the first end, a central axis extending through the first end and the second end, an accommodation space for accommodating a head of the bone anchoring element, an opening at the second end sized to facilitate insertion of the head therethrough, and a recess at the first end for receiving the rod, the recess forming two legs; and

a pressure member arranged at least partially in the accommodation space, the pressure member being adjustable from a first configuration where a topmost end of the pressure member is at a first axial position and an inserted head is pivotable in the accommodation space but prevented from removal from the accommodation space through the opening, to a second configuration where the topmost end of the pressure member is at a second axial position below the first axial position and the pressure member exerts pressure onto the inserted head to provisionally lock the inserted head;

wherein at the second configuration, a latching connection is formed between the pressure member and the receiving part to at least temporarily prevent the pressure member from being adjusted back towards the first configuration, and wherein the latching connection is releasable by exerting a force in a direction transverse to the central axis from outside the receiving part on the pressure member to adjust the pressure member from the second configuration back towards the first configuration.

2. The coupling device of claim 1 , wherein the pressure member comprises a head contacting portion configured to contact the head when the pressure member is in the accommodation space, and two arms extending away from the head contacting portion, wherein each of the legs defines a slot arranged between an outer wall and an inner wall of the legs, and wherein each of the arms extends axially into a respective one of the slots.

3. The coupling device of claim 2 , wherein the pressure member comprises a first engagement portion and the receiving part comprises a second engagement portion, and wherein the latching connection is established when one of the first or second engagement portions snaps below the other one of the first or second engagement portions.

4. The coupling device of claim 3 , wherein the first engagement portion is located at the arms of the pressure member, and the second engagement portion is located in the slot of the receiving part.

5. The coupling device of claim 2 , wherein respective free ends of the arms of the pressure member are exposed to the outside at the first end of the receiving part.

6. The coupling device of claim 2 , wherein the arms are flexible, and wherein the latching connection is releasable by exerting force onto the arms in respective directions transverse to the central axis.

7. The coupling device of claim 2 , wherein an outer wall of each of the legs of the receiving part comprises a transverse opening that exposes a portion of the arms of the pressure member extending into the slot to the outside for applying the forces from outside the receiving part thereto.

8. The coupling device of claim 1 , wherein the pressure member is adjustable to the second configuration by exerting an axial force onto the topmost end of the pressure member.

9. The coupling device of claim 1 , wherein the pressure member can further assume a third configuration that defines an insertion position where the topmost end of the pressure member is at an axial position above the first axial position and where a head is insertable through the opening into the accommodation space.

10. The coupling device of claim 1 , wherein the first configuration defines a pre-locking position where the pressure member blocks a portion of the opening to prevent an inserted head from being removed from the accommodation space through the opening.

11. The coupling device of claim 1 , wherein in the first configuration, the pressure member exerts a pressure on the inserted head to restrict pivoting of the head, while the recess of the receiving part remains substantially unobstructed such that a rod is insertable into and movable in the recess.

12. The coupling device of claim 11 , wherein the coupling device is configured to maintain the first configuration without engaging a rod, fixation member, or instrument.

13. The coupling device of claim 1 , wherein the receiving part comprises extensions that respectively extend above the legs, and wherein each of the extensions comprises an abutment for limiting upward movement of the pressure member in the first configuration.

14. The coupling device of claim 1 , wherein the receiving part and the pressure member are inseparably interconnected with each other.

15. The coupling device of claim 1 , wherein the receiving part and the pressure member are monolithically formed with one another.

16. The coupling device of claim 1 , wherein the receiving part and the pressure member are formed together by using an additive manufacturing method.

17. A bone anchoring device comprising:

the coupling device of claim 1 ; and

the bone anchoring element comprising the head and a shank for anchoring in bone, wherein the head has a spherically-shaped outer surface portion that at least partially faces a free end of the shank to facilitate pivoting in the accommodation space.

18. A coupling device for coupling a rod to a bone anchoring element, the coupling device comprising:

a receiving part having a first end and a second end below the first end, a central axis extending through the first end and the second end, an accommodation space for accommodating a head of the bone anchoring element, an opening at the second end, a recess at the first end for receiving the rod, the recess forming two legs, a downwardly facing surface, and an upwardly facing surface monolithically formed with the downwardly facing surface; and

a pressure member arranged at least partially in the accommodation space, the pressure member being movable axially relative to the receiving part from a first axial position where an inserted head is pivotable in the accommodation space to a second axial position below the first axial position where the pressure member exerts pressure onto the inserted head to provisionally lock the inserted head;

wherein a range of the axial movement of the pressure member is limited in the receiving part by the downwardly and upwardly facing surfaces, and wherein the receiving part and the pressure member are only separable from one another by permanently deforming or damaging at least one of the receiving part or the pressure member.

19. A coupling device for coupling a rod to a bone anchoring element, the coupling device comprising:

a receiving part having an accommodation space for accommodating a head of the bone anchoring element, an opening at the second end, and a recess at the first end for receiving the rod, the recess forming two legs; and

a pressure member arranged at least partially in the accommodation space, the pressure member being movable relative to the receiving part from a first axial position where an inserted head is pivotable in the accommodation space to a second axial position below the first axial position where the pressure member exerts pressure onto the inserted head to provisionally lock the inserted head;

wherein the pressure member is formed at a position relative to the receiving part where a first abutting surface of the receiving part prevents axial movement of the pressure member in a first direction and a second abutting surface of the receiving part prevents axial movement of the pressure member in a second direction opposite the first direction, and wherein the receiving part and the pressure member are only separable from one another by permanently deforming or damaging at least one of the receiving part or the pressure member.

20. The coupling device of claim 19 , wherein the receiving part and the pressure member are formed together using an additive manufacturing method.

21. The coupling device of claim 19 , wherein the receiving part and the pressure member are formed as a monolithic unit, and wherein a portion of the monolithic unit is thereafter removed to render the receiving part and the pressure member movable relative to one another but only separable from one another by permanently deforming or damaging at least one of the receiving part or the pressure member.