Bone anchoring device and stabilization device for bone parts or vertebrae comprising such a bone anchoring device

Abstract

A stabilization device for bone parts or vertebrae includes two bone anchoring devices for anchoring in the bone parts or vertebrae. At least one of the bone anchoring devices includes an anchoring element with an anchoring section for anchoring in a bone part or a vertebra and a head, and a receiving part for receiving a stabilization rod. The receiving part has a seat for receiving the head so that the head can pivot with respect to the receiving part. The stabilization device includes a first pressure element which is movable in the receiving part so that it can be pressed onto the head to lock the angular position of the head. The stabilization device includes at least two stabilization rod sections, and at least two guiding channels within the receiving part which have a distance from each other for guiding through the at least two stabilization rod sections so that the rod sections do not touch each other.

1 - 28 . (canceled) 
     
     
         29 . A polyaxial bone anchoring device comprising:
 an anchoring element comprising a shank for anchoring a bone part or a vertebra and a head;   a receiving part configured to pivotably receive the head, the receiving part having a first end, a second end opposite to the first end, a coaxial bore, a first recess and a second recess each adjacent to the first end for receiving a rod, and a central axis extending through the first end and the second end, the receiving part comprising two legs separated by the coaxial bore and the first and second recesses, a longitudinal axis of the recesses being substantially perpendicular to the central axis;   a first clamping part having a rod supporting surface that extends from the coaxial bore into the first recess when assembled in the receiving part;   a second clamping part configured to exert pressure on the rod when the rod is in the coaxial bore; and   a locking device configured to exert pressure on the second clamping part to secure the rod in the coaxial bore;   wherein, when the bone anchoring device is assembled, the first clamping part is located between the head of the anchoring element and the second clamping part.   
     
     
         30 . The polyaxial bone anchoring device of  claim 29 , wherein the rod supporting surface has a longitudinal axis perpendicular to the central axis. 
     
     
         31 . The polyaxial bone anchoring device of  claim 29 , wherein the first clamping part further comprises a coaxial bore that is coaxial to the central axis. 
     
     
         32 . The polyaxial bone anchoring device of  claim 29 , wherein rod supporting surface of the first clamping part extends from the coaxial bore of the receiving part into the second recess. 
     
     
         33 . The polyaxial bone anchoring device of  claim 32 , wherein the second clamping part extends from the coaxial bore of the receiving part into the first recess and into the second recess. 
     
     
         34 . The polyaxial bone anchoring device of  claim 29 , wherein the second clamping part has a rod facing surface having a longitudinal axis perpendicular to the central axis. 
     
     
         35 . The polyaxial bone anchoring device of  claim 29 , wherein respective free ends of the first clamping part and the second clamping part extend into the first recess such that the free ends are flush with an outer surface of the receiving part. 
     
     
         36 . The polyaxial bone anchoring device of  claim 29 , wherein the second clamping part is configured to be rotatably coupled to the locking device. 
     
     
         37 . The polyaxial bone anchoring device of  claim 29 , wherein the first clamping part further comprises a first portion that is configured to exert pressure on the head. 
     
     
         38 . The polyaxial bone anchoring device of  claim 37 , wherein the first portion has a recess at a side opposite to the rod supporting surface and the recess is configured to accommodate a portion of the head. 
     
     
         39 . A spinal stabilization system comprising at least two polyaxial bone anchoring devices according to  claim 29  and a rod,
 wherein the rod comprises a nickel-titanium alloy. 
 
     
     
         40 . The polyaxial bone anchoring device of  claim 37 , wherein the first portion has a cylindrical outer surface configured to be received in the coaxial bore and a spherical inner surface configured to engage the head.