Dynamic anchoring device and dynamic stabilization device for bones, in particular for vertebrae, with such an anchoring device

Abstract

A dynamic anchoring device is described. An element with a shank for anchoring in a bone or a vertebra and with a head connected to the shank is provided with a receiving part for the head and with an elastomeric pressure element acting on the head. The pressure element is formed and located in such a way that, upon a movement of the element from a first angular position of the shank relative to the receiving part into a second angular position, it exerts a return force on the head. Further, a dynamic stabilization device, in particular for vertebrae, is provided. In such a stabilization device, a rod is connected two anchoring devices. At least one of the anchoring devices is constructed as dynamic anchoring element.

1 . A dynamic anchoring device comprising
 an element having a shank for anchoring in a bone or a vertebra and a head connected to the shank,   a receiving part for receiving the head,   and a pressure element acting on the head,   wherein the pressure element is formed so as to be resilient in such a way that upon a movement of the element from a first angular position of the shank relative to said receiving part into a second angular position the pressure element exerts a return force onto the head to urge the element towards the first angular position.   
     
     
         2 . The dynamic anchoring device according to  claim 1 , wherein the pressure element acts on a side of the head facing away from the shank. 
     
     
         3 . The dynamic anchoring device according to  claim 1 , wherein the pressure element is formed of an elastomer. 
     
     
         4 . The dynamic anchoring device according to  claim 1 , wherein the pressure element comprises at least one spring element. 
     
     
         5 . The dynamic anchoring device according to  claim 1 , wherein the head comprises a flat surface on a side facing away from the shank and the pressure element comprises a flat surface cooperating therewith. 
     
     
         6 . The dynamic anchoring device according to  claim 5 , wherein the head comprises a collar on the side facing away from the shank. 
     
     
         7 . The dynamic anchoring device according to  claim 1 , wherein the receiving part comprises a support surface to support the head, the support surface and/or the head being polished or coated to reduce friction. 
     
     
         8 . The dynamic anchoring device according to  claim 1 , further comprising a rigid element acting on the pressure element on a side of the pressure element opposite to the head. 
     
     
         9 . The dynamic anchoring device according to  claim 1 , wherein the head and the shank are separate parts. 
     
     
         10 . The dynamic anchoring device according to  claim 9 , wherein the head has a central axis and the shank is connectable to the head at a predetermined angle α to the central axis. 
     
     
         11 . The dynamic anchoring element according to  claim 1 , wherein the pressure element is substantially cylindrical and comprises a first section which is resilient and a second section which is rigid and which is located on a side opposite to the head. 
     
     
         12 . The dynamic anchoring device according to  claim 11 , wherein the second section comprises a U-shaped recess to receive a rod to be received in the receiving part, the recess forming two free legs and wherein a depth of the recess is greater than the diameter of the rod. 
     
     
         13 . The dynamic anchoring device according to  claim 11 , wherein the first section and the second section are separate parts. 
     
     
         14 . The dynamic anchoring device according to  claim 1 , wherein the pressure element is formed by an insert made of an elastomer and having a support surface for the head to rest against. 
     
     
         15 . The dynamic anchoring device according to  claim 1 , wherein a second elastic pressure element is provided encompassing the head in a ring shape. 
     
     
         16 . The dynamic anchoring device according to  claim 15 , wherein the second pressure element is shaped as O-ring or as a molded ring. 
     
     
         17 . The dynamic anchoring device according to  claim 1 , wherein the receiving part comprises a U-shaped recess for inserting a rod and the pressure element is arranged between the head and the rod when the rod is inserted into the receiving part. 
     
     
         18 . The dynamic anchoring device according to  claim 17 , wherein the pressure element is pre-compressed by the rod when the rod lies on the bottom of the U-shaped recess. 
     
     
         19 . The dynamic anchoring device according to  claim 1 , wherein the pressure element is arranged in the receiving part under bias. 
     
     
         20 . A dynamic stabilization device for bones, in particular for vertebrae, having at least two anchoring devices connected to a rod,
 wherein at least one of the anchoring devices comprises   an element having a shank for anchoring in a bone or a vertebra and a head connected to the shank,   a receiving part for receiving the head,   and a pressure element acting on the head,   wherein the pressure element is formed so as to be resilient in such a way that upon a movement of the element from a first angular position of the shank relative to said receiving part into a second angular position the pressure element exerts a return force onto the head to urge the element towards the first angular position.   
     
     
         21 . The dynamic stabilization device according to  claim 20 , wherein a spring element is provided on the rod. 
     
     
         22 . The dynamic stabilization device according to  claim 21 , wherein the spring element is arranged between the anchoring devices. 
     
     
         23 - 26 . (canceled) 
     
     
         27 . A dynamic anchoring device comprising:
 an element having a shank for anchoring in a bone or a vertebra and a head connected to the shank,   a receiving part for receiving the head, the receiving part being connected to an external device,   a pressure element acting on the head,   wherein the pressure element is formed so as to be resilient in such a way that when the bone or the vertebra moves a force acting on the external device is prevented from being transmitted to the shank.   
     
     
         28 . A dynamic anchoring device comprising
 an element having a shank for anchoring in a bone or a vertebra and a head connected to the shank,   a receiving part for receiving the head, the receiving part having a longitudinal axis and a bore hole through which the shank is inserted,   and a resilient pressure element located along the longitudinal axis and acting on the head.   
     
     
         29 . A dynamic stabilization device for bones, in particular for vertebrae, having at least two anchoring devices connected to a rod,
 wherein at least one of the anchoring devices comprises:   an element having a shank for anchoring in a bone or a vertebra and a head connected to the shank,   a receiving part for receiving the head, and   a resilient pressure element acting on the head,   wherein the pressure element is located between the rod and the head when the devices are connected to the rod.   
     
     
         30 - 31 . (canceled)