Rod-like element for application in spinal or trauma surgery, and stabilization device with such a rod-like element

Abstract

A rod-shaped element for use in spinal or trauma surgery, having a first section for connecting to a first bone anchoring element and a second section for connecting to a second bone anchoring element is described. The rod-shaped element also includes a first elastic flexible element that is capable of elastic deformation when a force acts on it transverse to the rod axis. The first section and the second section are capable of shifting relative to each other in the direction of the rod axis. In a stabilization device for use in spinal or trauma surgery, the rod-shaped element allows for a controlled motion of the parts to be stabilized relative to each other so flexural motion is adjusted separately from the adjustment of the mobility in axial direction.

1 . A rod-shaped element having a rod axis, for use in spinal or trauma surgery, comprising
 a first section connected to a first bone anchoring element;   a second section connected to a second bone anchoring element;   and a first flexible element capable of elastic deformation when a force acts on said flexible element transversely to the rod axis,   wherein the first section and the second section are capable of constantly moving relative to each other in the direction of the rod axis.   
   
   
       2 . A rod-shaped element according to  claim 1 , comprising a second flexible element, wherein said second flexible element dampens the axial motion of the first section relative to the second section. 
   
   
       3 . A rod-shaped element according to  claim 1 , comprising a stop for limiting the axial motion. 
   
   
       4 . A rod-shaped element according to  claim 1 , wherein said first flexible element is capable of elastic deformation when a force acts on said first flexible element transversely as well as in the direction of the rod axis. 
   
   
       5 . A rod-shaped element according to  claim 1 , wherein said first flexible element is essentially cylindrical in shape and is connected to one rigid section on each of its ends. 
   
   
       6 . A rod-shaped element according to  claim 5 , wherein said second rigid section has two ends with a sleeve on each end that is capable of shifting on said rigid section. 
   
   
       7 . A rod-shaped element according to  claim 2 , wherein the second flexible element includes a damping ring. 
   
   
       8 . A rod-shaped element according to  claim 7 , wherein said damping ring is made of an elastic material. 
   
   
       9 . A rod-shaped element according to  claim 5 , further comprising a spring having a first connection to the first section and a second connection to the second section, said spring extending in an axial direction. 
   
   
       10 . A rod-shaped element according to  claim 9 , wherein the first connection to said first section comprises an outer thread which cooperates with an internal thread of the first section. 
   
   
       11 . A rod-shaped element according to  claim 10 , wherein the second connection to the second section comprises a bore which is continuous in the radial direction and a pin. 
   
   
       12 . A rod-shaped element according to any one of the  claim 2 , wherein the first flexible element and the second flexible element have different spring constants in axial direction of the rod. 
   
   
       13 . A rod-shaped element according to  claim 1 , wherein the first section and the second section are capable of shifting relative to each other in the direction of the circumference. 
   
   
       14 . A rod-shaped element according to  claim 1 , wherein the first section and the second section are secured against torsion in the direction of the circumference. 
   
   
       15 . A stabilization device with a first bone anchoring element and a second bone anchoring element and a rod-shaped element according to  claim 1 . 
   
   
       16 . A stabilization device with a first bone anchoring element and a second bone anchoring element and a rod-shaped element according to  claim 2 . 
   
   
       17 . A method of stabilizing two bone or vertebrae comprising:
 anchoring a first bone anchoring element having a receiver member in a bone or vertebrae;   anchoring a second bone anchoring element having a receiver member in a second bone or vertebrae;   inserting a rod-shaped element onto said receiving members of said bone anchoring elements, wherein said rod-shaped element has a rod axis and comprises a first section connected to said first bone anchoring element; a second section connected to a second bone anchoring element;   and a first flexible element between said first section and said second section capable of elastic deformation when a force acts on said flexible element transversely to the rod axis,   wherein the first section and the second section are capable of shifting relative to each other in the direction of the rod axis.   
   
   
       18 . A method of stabilizing bone or vertebrae according to  claim 17 , wherein said flexible element is capable of elastic deformation when a force acts on said flexible element traversely as well as in the direction of the rod axis. 
   
   
       19 . A method of stabilizing bone or vertebrae according to  claim 17 , further comprising a second flexible element whereby said second flexible element dampens the axial shifting motion of the first section relative to said second section. 
   
   
       20 . A method of stabilizing bone or vertebrae comprising:
 anchoring a first pedicle screw to a first bone or vertebrae;   anchoring a second pedicle screw to a second bone or vertebrae;   inserting a rod-shaped element having an elastic section into said first pedicle screw and said second pedicle screw,whereby the elasticity of the connection between the bone anchoring elements with respect to the translation motion is decoupled from the flexural elasticity of the rod.   
   
   
       21 . (canceled)