Bone anchoring device

A method of coupling a rod to bone using a bone anchoring device comprising an anchoring element comprising a shank for anchoring to bone and a head, a receiving part having a first end, a second end below the first end, a central axis extending between the first and second ends, a channel at the first end for receiving the rod, and an accommodation space at the second end for accommodating the head of the anchoring element, and a pressure element positionable at least partially in the accommodation space to exert pressure on the head in the receiving part, wherein the pressure element is configured to extend to an axial position relative to the receiving part that is lower than an axial position of a portion of the head having a greatest diameter measured in a direction perpendicular to the central axis, and a locking element, the method comprising:

• anchoring the shank of the anchoring element to bone;
• pivoting the receiving part relative to the head when the head is held in the accommodation space, wherein the head comprises a first cooperating surface spaced apart axially from a free end of the head that is engageable with a second cooperating surface that is separable from the pressure element to limit pivoting of the head relative to the receiving part to a single plane;
• inserting the rod into the channel of the receiving part;
• and
• advancing the locking element in the channel to lock respective positions of the head and the rod relative to the receiving part.

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

• an anchoring element comprising a shank for anchoring to bone and a head;
• a receiving part having a first end, a second end below the first end, a central axis extending between the first and second ends, a channel at the first end for receiving the rod, and an accommodation space at the second end for accommodating the head of the anchoring element;
• and
• a pressure element positionable at least partially in the accommodation space, the pressure element having a head contacting surface that is at least partially expandable to engage and exert pressure on the head in the receiving part;
• wherein the head is insertable through the second end of the receiving part into the accommodation space, and wherein the pressure element is movable to and configured to be held at a pre-locking position to restrict the head from being removed from the receiving part;
• and
• wherein the head is pivotable relative to the receiving part, wherein the head comprises a first cooperating surface that is engageable with a second cooperating surface to limit pivoting of the head relative to the receiving part to a single plane, and wherein the pressure element defines at least one lateral opening through which the second cooperating surface is configured to extend to engage the head.