Patent ID: 8192470

Claim:
A bone anchoring device comprising: a bone anchoring element having a shaft for anchoring to a bone and a head; a receiving part for coupling a rod to the bone anchoring element, wherein the receiving part comprises: a first portion defining a U-shaped recess for receiving the rod and forming two legs each having a free end; and a second portion defining an accommodation space for accommodating the head, the second portion having a free end and being flexible so as to allow introduction of the head through its free end into the accommodation space and clamping of the head in the accommodation space; and a locking ring embracing the second portion and comprising two projections offset by 180° which project into the U-shaped recess when the head is not clamped; wherein when the head is located in the accommodation space and the locking ring is at a resting position relative to the second portion, the bone anchoring element is held temporarily at a preliminary angular position relative to the receiving part that remains adjustable by moving the receiving part and the head relative to one another, wherein when the head is located in the accommodation space and the locking ring is at a locking position relative to the second portion, the locking ring compresses the second portion to clamp the head in the accommodation space and to lock the angular position between the bone anchoring element and the receiving part, and wherein the locking ring is configured to be mounted to the receiving part from the free end of the second portion, and is configured to be moved from the resting position to the locking position by exerting pressure with the rod onto the locking ring.