Patent ID: 8562652

Claim:
A dynamic anchoring device comprising: an anchoring element having a shank for anchoring in a bone or a vertebra and a head connected to the shank; a rod, a receiving part defining a bore for receiving the head, the receiving part comprising a shaped recess for inserting the rod; a fixation screw for fixing the rod in the recess; and a pressure element located inside the bore and acting on the head, the pressure element comprising a resilient portion having a first side and a second side; wherein when the rod is fixed in the recess by the fixation screw, the anchoring element is movable from a first angular position to a second angular position different from the first angular position, the movement exerting a compression force on the first side of the resilient portion and releasing pressure on the second side of the resilient portion, wherein the first side of the resilient portion exerts a return force onto the head in response to the compression force urging the anchoring element towards the first angular position; wherein a contact position of the anchoring element relative to the resilient portion is substantially constant during movement of the anchoring element from the first angular position to the second angular position.