Patent ID: 7591839
Filing Date: 2009-09-22
Classification: A61B

Abstract:
1. A bone anchoring device, comprising: a bone anchoring element having a shank with a first head directly fixed to the shank; a receiving member having a recess; a second head in the recess of the receiving member and pivotally arranged relative to the receiver member, the first head located in the second head; at least one securing element configured to fix the second head from pivoting in the recess of the receiving member; and an elastic pressure element configured to pivotally couple the anchoring element, including the first head and the shank, and the second head between a first position and a plurality of second positions angularly offset from the first position; wherein when the second head is fixed from pivoting in the recess of the receiver member, the first head and the shank are together pivotable relative to the second head between the first position and the plurality of second positions with the elastic pressure element biasing the first head and the shank from the plurality of second positions wherein the elastic pressure element is compressed on one side more than an opposite side to the first position wherein the compressive forces exerted on the elastic pressure element are balanced to provide a resting position of the first head and the shank in the first position.