Intervertebral linking device

Abstract

One embodiment includes at least a fixed element designed to be secured to a vertebra or sacrum, at least a mobile linking element and at least an intermediate element that articulates the mobile element relative to the fixed element. The intermediate element is received in an internal volume of the mobile element and is deformable, so as to be introduced by impingement into the inner volume. The fixed element is received at least partly in an internal volume of the intermediate element and has a position for use wherein said fixed element has three degrees of freedom in rotation, but is linked in translation, relative to the intermediate element.

1 . Intervertebral linking device to connect at least two bones of the spine to one another, comprising: 
 at least one fixed which is to be secured to a vertebra of the spine or to a sacrum of the spine,    at least one mobile linking element suitable for being displaced relative to each fixed element,    at least one intermediate element permitting the articulation of each mobile linking element relative to the at least one fixed element,    wherein each intermediate element is received, in an internal volume of a corresponding one of the at least one mobile linking element, or of a corresponding one of the at least one fixed element, the intermediate element being deformable to be placed into the internal volume by impaction,    and wherein the at least one fixed element, or the at least one mobile linking element, is received at least partially in an internal volume of the intermediate element having a mutual position of use with three degrees of freedom in rotation relative to the intermediate element while remaining linked in translation and a mutual position of introduction in which the corresponding one of the at least one fixed element, or the corresponding one of the at least one mobile element, has three degrees of freedom in rotation and in translation relative to the intermediate element.    
     
     
         2 . Linking device according to  claim 1 , wherein the intermediate element assumes the form of a cup.  
     
     
         3 . Linking device according to  claim 2 , wherein the internal volume of the intermediate cup is bordered by a truncated spherical surface.  
     
     
         4 . Linking device according to  claim 3 , wherein the intermediate cup has a truncated spherical external surface, which is concentric with the internal surface.  
     
     
         5 . Linking device according to  claim 4 , wherein the internal surface and the external surface define a wall of the intermediate cup.  
     
     
         6 . Linking device according to  claim 5 , wherein the thickness of the wall is from 1 to 1.5 mm.  
     
     
         7 . Linking device according to  claim 1 , wherein the intermediate element is produced from polyethylene.