Intervertebral prosthesis especially for a neck vertebral support

Abstract

Intervertebral prosthesis, in particular for the cervical spine, consisting basically of a first cover plate ( 1 ) to be connected to a first vertebral body, a second cover plate ( 2 ) to be connected to the second vertebral body, and a prosthesis core ( 10 ) which is held by a seat ( 5, 6, 7 ) of the first cover plate ( 1 ) and forms an articulation ( 20, 21 ) with the second cover plate ( 2 ). The core ( 10 ) is movable in the AP direction relative to the first cover plate ( 1 ). Mobility can also be provided in the lateral direction and rotational direction.

1 . Intervertebral prosthesis, in particular for the cervical spine, consisting basically of a first cover plate ( 1 ,  31 ) to be connected to a first vertebral body, of a second cover plate ( 2 ,  32 ) to be connected to the second vertebral body, and of a prosthesis core ( 10 ,  34 ) which is held by a seat of the first cover plate ( 1 ,  31 ) and forms an articulation with the second cover plate ( 2 ,  32 ), characterized in that the core ( 10 ,  34 ) is movable relative to the first cover plate ( 1 ,  31 ) at least in the AP direction.  
     
     
         2 . Prosthesis according to  claim 1 , characterized in that the seat has a movement-limiting device cooperating with an edge ( 11 ,  36 ) of the core ( 10 ,  34 ).  
     
     
         3 . Prosthesis according to  claim 2 , characterized in that the movement-limiting device is designed as a guide device in the AP direction.  
     
     
         4 . Prosthesis according to one of  claims 1  to  3 , characterized in that the guide device is formed by two opposite, parallel lateral guide rails ( 7 ) for guiding in the AP direction.  
     
     
         5 . Prosthesis according to  claim 4 , characterized in that the lateral guide rails ( 7 ) are undercut, and the core ( 10 ) has a ridge ( 11 ) engaging in the undercut.  
     
     
         6 . Prosthesis according to  claim 4  or  5 , characterized in that the first cover plate ( 1 ) has a dorsal limit stop ( 21 ) limiting the movement of the core ( 10 ).  
     
     
         7 . Prosthesis according to one of  claims 4  to  6 , characterized in that the first cover plate ( 1 ) has a ventral limit stop ( 14 ) limiting the movement of the core ( 10 ) and removable from its limit-stop position.  
     
     
         8 . Prosthesis according to  claim 2  or  3 , characterized in that the core ( 34 ) has a recess ( 35 ) which cooperates with a projection ( 37 ,  37   a ) of the first cover plate ( 31 ).  
     
     
         9 . Prosthesis according to  claim 8 , characterized in that the recess ( 35 ) has an elongate shape extending in the AP direction.  
     
     
         10 . Prosthesis according to  claim 8  or  9 , characterized in that the projection ( 37 ,  37   a ) and the recess ( 35 ) have interacting undercuts ( 36 ,  38 ).  
     
     
         11 . Prosthesis according to one of  claims 1  to  10 , characterized in that the articulation impedes or inhibits the rotation movement between the upper cover plate ( 2 ,  32 ) and the prosthesis core ( 10 ,  34 ), and the core ( 10 ,  34 ) can pivot about the vertical axis relative to the first cover plate ( 1 ).  
     
     
         12 . System of intervertebral prostheses, in particular for the spinal column, consisting basically of a first cover plate to be connected to a first vertebral body, of a second cover plate to be connected to the second vertebral body, and of a prosthesis core which is held by a seat of the first cover plate and forms an articulation with the second cover plate, characterized in that, in addition to the intervertebral prosthesis types according to one of  claims 1  to  11 , the system includes types of corresponding external configuration which do not have AP mobility between the prosthesis core and the first cover plate.  
     
     
         13 . System according to  claim 12 , characterized in that the cover plates of the corresponding types with/without AP mobility are identical and the core is different.  
     
     
         14 . System according to  claim 12 , characterized in that the second cover plate and the prosthesis core of the corresponding types with/without AP mobility are identical and the first cover plate is different.  
     
     
         15 . System according to  claim 12 , characterized in that all three components are identical and a limit stop, which limits the mobility of the prosthesis core in the ventral direction, is different.