Patent ID: 9345516
Filing Date: 2016-05-24
CPC Classification: A61B

Claim Text:
1. A polyaxial bone anchoring device comprising: an anchoring element having a shaft for anchoring in a bone and a head; a receiving part having a first end and a second end, a channel for receiving a rod therein, a bore extending from the first end towards the second end, a seat for receiving the head, and at least one threaded through hole transverse to the bore; a pressure element configured to be arranged in the bore and to exert pressure onto the head when the head and the pressure element are in the receiving part, such that the head is pivotable with respect to the receiving part and can be locked at an angle relative to the receiving part by the pressure element, the pressure element having at least one hole configured to at least partially align with the through hole of the receiving part; and at least one set screw having a tapered portion and being configured to be inserted into the through hole of the receiving part; wherein when the head and the pressure element are in the receiving part, the set screw is threadable into the through hole to a first position where the set screw engages the pressure element at the hole such that a first force is exerted by the pressure element onto the head that maintains the head at an adjustable angular position relative to the receiving part by friction prior to locking the head relative to the receiving part; wherein the set screw is threadable into the through hole past the first position to a second position where the set screw engages the pressure element at the hole such that a second force greater than the first force is exerted by the pressure element onto the head; and wherein a surface of the pressure element that engages the set screw in the first position is tapered with respect to a central axis of the receiving part, and the tapered portion of the set screw is configured to engage the pressure element at the hole.