Intervertebral disc prosthesis

Abstract

A flexible prosthetic cover shaped to form a replacement nucleus pulposis for an intervetebral disc with an aperture for the introduction of filling material therein, and an elongate introducer member configured to pass into the aperture is provided. The cover has a strengthened portion substantially opposite the aperture for engaging the distal end of the member, the strengthened portion and the distal end being arranged to interlock, for facilitating orientation of the cover, for example so as to prevent relative rotation there between.

What is claimed is: 
     
         1 . A prosthetic cover for an intervertebral disc comprising an edge portion being a resiliently deformable annular sleeve shaped to fit within a disc annulus and a pair of opposed flexible central portions each joining the edge portion at an edge of the sleeve;
 wherein the central portions are formed from a flexible thin material and the edge portion comprises a circumferential ring which is thicker than the central portions;   wherein the edge portion includes an aperture for the introduction of a filling material; and   wherein the annular sleeve is pressurised against the disc annulus on injection of a filling material into the cover.   
     
     
         2 . The prosthetic cover as claimed in  claim 1  wherein the annular sleeve is generally in the shape of a car tyre. 
     
     
         3 . The prosthetic cover as claimed in  claim 1 , wherein in use, the edges of the annular sleeve overlap superior and inferior vertebral end plates. 
     
     
         4 . The prosthetic cover as claimed in  claim 1 , wherein the central portions are arranged, when the cover is filled with a filling material, to allow the filling material to pass therethrough. 
     
     
         5 . The prosthetic cover as claimed in  claim 4 , wherein the central portions are formed of a material arranged to break under filling pressure. 
     
     
         6 . The prosthetic cover as claimed in  claim 4  wherein the central portions are formed from a material which is absorbable by the body. 
     
     
         7 . The prosthetic cover as claimed in  claim 4  wherein the central portions are adapted to allow the filling material to easily pass therethrough and come into contact with vertebral end plates. 
     
     
         8 . The prosthetic cover as claimed in  claim 1  further comprising a strengthened portion located in the edge portion substantially opposite the aperture, the strengthened portion being adapted to interlock with an elongate introducer member for facilitating orientation of the cover. 
     
     
         9 . The prosthetic cover as claimed in  claim 1  wherein the aperture comprises a valve. 
     
     
         10 . A prosthetic cover for an intervertebral disc comprising an edge portion being a resiliently deformable annular sleeve shaped to fit within a disc annulus and a pair of opposed flexible central portions each joining an edge of the sleeve, the edge portion including an aperture for the introduction of a filling material, wherein the annular sleeve is pressurised against the disc annulus on injection of a filling material into the cover. 
     
     
         11 . The prosthetic cover as claimed in  claim 10  wherein the annular sleeve is generally in the shape of a car tyre. 
     
     
         12 . The prosthetic cover as claimed in  claim 10 , wherein in use, the edges of the annular sleeve overlap superior and inferior vertebral end plates. 
     
     
         13 . The prosthetic cover as claimed in  claim 10 , wherein the central portions are arranged, when the cover is filled with a filling material, to allow the filling material to pass therethrough. 
     
     
         14 . The prosthetic cover as claimed in  claim 13 , wherein the central portions are formed of a material arranged to break under filling pressure. 
     
     
         15 . The prosthetic cover as claimed in  claim 13  wherein the central portions are formed from a material which is absorbable by the body. 
     
     
         16 . The prosthetic cover as claimed in  claim 13  wherein the central portions are adapted to allow the filling material to easily pass therethrough and come into contact with vertebral end plates. 
     
     
         17 . The prosthetic cover as claimed in  claim 10  further comprising a strengthened portion located in the edge portion substantially opposite the aperture, the strengthened portion being adapted to interlock with an elongate introducer member for facilitating orientation of the cover. 
     
     
         18 . The prosthetic cover as claimed in  claim 10  wherein the aperture comprises a valve. 
     
     
         19 . A prosthetic cover for an intervertebral disc comprising an edge portion being a resiliently deformable annular sleeve being shaped to fit within a disc annulus, and a pair of opposed flexible central portions each joining an edge of the sleeve, the edge portion including an aperture for the introduction of a filling material, wherein, in use, the edges of the annular sleeve overlap superior and inferior vertebral end plates.