Artificial disc

Abstract

An intervertebral artificial disc is provided with a first endplate having a plurality of protrusions for attaching to an adjacent vertebrae and an extension portion extending towards a second adjacent vertebrae. A second endplate is provided with a plurality of protrusions for attaching to a second adjacent vertebrae and an extension portion extending towards the first adjacent vertebrae. A flexible member having an upper portion and a lower portion and a slider plate positioned within the upper portion of the flexible member is also provided. The extension portion of the first endplate is adapted to fit within a first cavity in the upper portion of the flexible member and the extension portion of the second endplate is adapted to fit within a second cavity in the lower portion of the flexible member.

What is claimed is: 
     
         1 . An intervertebral artificial disc assembly for positioning within intervertebral space between a first and second vertebra comprising:
 a first endplate having a first surface configured to engage the first vertebrae and an extension portion extending opposite the first surface of the first endplate;   a second endplate having a first surface configured to engage the second vertebrae and an extension portion extending opposite the first surface of the second endplate;   a core element configured to receive the extension portion of the first endplate and the extension portion of the second endplate; and   a slider plate positioned in the core element, wherein the extension portion of the first endplate is configured with a curvature which corresponds to a curvature associated with the slider plate.   
     
     
         2 . The intervertebral artificial disc assembly of  claim 1 , wherein the first endplate of the disc assembly comprises one or more keels that engage with the first vertebrae. 
     
     
         3 . The intervertebral artificial disc assembly of  claim 2 , wherein the first endplate of the disc assembly comprises at least a first keel and a second keel, wherein the first keel and the second keel are of a different shape from one another. 
     
     
         4 . The intervertebral artificial disc assembly of  claim 1 , wherein the extension portion of the first endplate is spaced apart from a base of the first endplate and fits into a cavity in an upper portion of the core element. 
     
     
         5 . The intervertebral artificial disc assembly of  claim 1 , wherein the extension portion of the second endplate is spaced apart from a base of the second endplate and fits into a cavity in a lower portion of the core element. 
     
     
         6 . The intervertebral artificial disc assembly of  claim 1 , wherein the core element is flexible. 
     
     
         7 . The intervertebral artificial disc assembly of  claim 1 , wherein the core element is composed of polycarbonate urethane. 
     
     
         8 . The intervertebral artificial disc assembly of  claim 1 , wherein the extension portion of the first endplate is configured to be smaller than the slider plate. 
     
     
         9 . The intervertebral artificial disc assembly of  claim 1 , wherein the extension portion of the second endplate is configured with a spherical surface received within a corresponding cavity in the core element. 
     
     
         10 . The intervertebral artificial disc assembly of  claim 1 , wherein the first and second endplates include one or more holes for receiving an instrument for positioning the disc assembly within the intervertebral space. 
     
     
         11 . An intervertebral artificial disc assembly for positioning within intervertebral space between a first and second vertebra comprising:
 a first endplate having a first surface configured to engage the first vertebrae and an extension portion extending opposite the first surface of the first endplate;   a second endplate having a first surface configured to engage the second vertebrae and an extension portion extending opposite the first surface of the second endplate;   a core element configured to receive the extension portion of the first endplate and the extension portion of the second endplate; and   a slider plate positioned in the core element, wherein the extension portion of the first endplate is configured with a flat surface which corresponds to a corresponding flat surface associated with the slider plate.   
     
     
         12 . The intervertebral artificial disc assembly of  claim 11 , wherein the first endplate of the disc assembly comprises one or more keels that engage with the first vertebrae. 
     
     
         13 . The intervertebral artificial disc assembly of  claim 12 , wherein the first endplate of the disc assembly comprises at least a first keel and a second keel, wherein the first keel and the second keel are of a different shape from one another. 
     
     
         14 . The intervertebral artificial disc assembly of  claim 11 , wherein the extension portion of the first endplate is spaced apart from a base of the first endplate and fits into a cavity in an upper portion of the core element. 
     
     
         15 . The intervertebral artificial disc assembly of  claim 11 , wherein the extension portion of the second endplate is spaced apart from a base of the second endplate and fits into a cavity in a lower portion of the core element. 
     
     
         16 . The intervertebral artificial disc assembly of  claim 11 , wherein the core element is flexible. 
     
     
         17 . The intervertebral artificial disc assembly of  claim 11 , wherein the core element is composed of polycarbonate urethane. 
     
     
         18 . The intervertebral artificial disc assembly of  claim 11 , wherein the extension portion of the first endplate is configured to be smaller than the slider plate. 
     
     
         19 . The intervertebral artificial disc assembly of  claim 11 , wherein the extension portion of the second endplate is configured with a spherical surface received within a corresponding cavity in the core element. 
     
     
         20 . The intervertebral artificial disc assembly of  claim 11 , wherein the first and second endplates include one or more holes for receiving an instrument for positioning the disc assembly within the intervertebral space.