Bone anchoring device

Abstract

A bone anchoring device is provided, comprising a bone anchoring element having a shaft for anchoring in the bone and a head; a receiving part for coupling a rod to the bone anchoring element, wherein the receiving part comprises a first portion with a first end and a second end and a U-shaped recess for receiving the rod, the recess extending from the first end in the direction of the second end thereby forming two free legs and a second portion at the side of the second end opposite to the first end for accommodating the head, the second portion having a free end and being flexible so as to allow introduction and clamping of the head; a locking ring embracing the second portion; wherein the head is locked by means of exerting pressure with the rod onto the locking ring resulting in compression of the second portion of the receiving part and wherein the locking ring is mounted to the receiving part from the free end of the second portion.

Description

technical field

[0001] The invention relates to a bone anchoring device comprising a bone anchor and a receiving part for connection to a rod. The head of the bone anchor is locked in the receiving part by pressing a part of the receiving part laterally around the head of the bone anchor by means of the locking ring pressed down by the rod. Said part of the clamping head of the receiving part is designed to allow the locking ring to be mounted from the free end of said part. The bone anchoring device may be implemented eg in the form of a polyaxial bone screw allowing pivotal movement of the head, or a uniaxial bone screw allowing rotational movement of the head about a single axis in the unlocked state, respectively. Background technique

[0002] Various designs of polyaxial bone screws are known, wherein each design has specific features and uses different locking principles.

[0003] DE 43 05 576 C1 describes a polyaxial bone screw with a screw part, a receiving part an...

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