Bone anchoring device

A method of anchoring a bone anchoring device to a bone, the method comprising:

• anchoring a bone anchoring assembly to the bone, the bone anchoring assembly comprising a receiving part for receiving a rod and an anchoring element, the receiving part having a first bore coaxial with a longitudinal axis and a second bore, the receiving part comprising a through hole;
• the anchoring element having a first end for insertion into the bone and a second end positionable within the second bore, the second end comprising a surface having a spherically shaped surface portion and a portion recessed from the spherically shaped surface portion;
• inserting at least one pin in the through hole, the pin protruding from an inner surface of the second bore and moving relative to the portion recessed from the spherically shaped surface portion of the second end of the anchoring element to provide pivoting of the anchoring element relative to the receiving part limited to a single plane;
• inserting a rod in the receiving part;
• adjusting an angular position of the anchoring element relative to the receiving part around a single axis of rotation;
• and
• inserting a pressure element in the receiving part, the pressure element configured to receive the rod;
• securing the anchoring element relative to the receiving part with a first fixation element transmitting pressure to the second end of the anchoring element in order to lock the angular position of the anchoring element relative to the receiving part by means of frictional force;
• and
• securing the rod in the pressure element with a second fixation element.

A bone anchoring device, comprising:

• a receiving part for receiving a rod, the receiving part having a first bore coaxial with a longitudinal axis, a second bore, and a seat comprising an inner wall;
• a pin configured to protrude from a hole recessed inside the inner wall of the seat;
• an anchoring element having a first end configured to attach to a bone and a second end comprising a head configured to be positioned against the seat to engage the pin when the pin is in the hole, the head comprising a surface having a spherically shaped surface portion and a portion recessed from the spherically shaped surface portion;
• wherein the inner wall of the seat is configured to be around the head and to seat the head when the head is positioned in the receiving part;
• wherein the bone anchoring device is adjustable between a first position, wherein the anchoring element is pivotable in multiple planes when the head is positioned in the seat and the pin is not in the hole and a second position, wherein pivoting of the anchoring element is limited to a single plane by a connection between the head of the anchoring element and the pin when the head is positioned in the seat and the pin is in the hole;
• and
• wherein the connection comprises a guiding surface of the portion recessed from the spherically shaped surface portion of the head that moves along a guiding surface of the pin resulting in a movement of the anchoring element relative to the receiving part being limited to the single plane.