Method of implanting an intervertebral spacer

Abstract

An intervertebral spacer adapted for implanting between adjacent vertebral bodies of a human spine as a load-bearing replacement for a spinal disc. The spacing member includes an external, non-porous, concavo-convex contour with respect to one dimension of the spacing member. The spacing member is preferably constructed from a rigid, non-resilient load-bearing material that is incapable of elastic deformation. The spacing member is inserted with the aid of a sheathed trocar device that is releasably attached to the spacer, to enable implantation and selective positioning of the spacer by the surgeon from the posterior side of the spine, without the need to retract the dural nerve or the posterior longitudinal ligament.

What is claimed is:  
     
         1 . A method of implanting an artificial intervertebral disc comprising: 
 (a) making an incision in an anulus of a human spinal column between adjacent vertebral bodies of said spinal column to thereby expose a space residing between said adjacent vertebral bodies;    (b) selecting a spacing member comprising an external concavo-convex contour with respect to one dimension of said spacing member, wherein the spacing member defines an imaginary arcuate centerline residing between opposing sides of the external concavo-convex contour of said spacing member, wherein the spacing member comprises an upper surface and a lower surface and a free insertion end, and wherein said spacing member includes a tapered portion such that said spacing member becomes progressively thinner toward said free insertion end of said spacing member;    (c) inserting the spacing member along an arcuate insertion path through the incision such that the imaginary arcuate centerline follows said arcuate insertion path during the insertion.    
     
     
         2 . A method of implanting an artificial intervertebral disc comprising: 
 (a) making an incision in an anulus of a human spinal column between adjacent vertebral bodies of said spinal column to thereby expose a space residing between said adjacent vertebral bodies;    (b) selecting a spacing member comprising an external concavo-convex contour with respect to one dimension of said spacing member, wherein the spacing member defines an imaginary arcuate centerline residing between opposing sides of the external concavo-convex contour of said spacing member;    (c) attaching a rigid inflexible member to the spacing member, said rigid inflexible member being straight along a majority length thereof, and using said rigid inflexible member for directing and inserting the spacing member along an arcuate insertion path through the incision such that the imaginary arcuate centerline follows said arcuate insertion path during the insertion.    
     
     
         3 . The method of  claim 2 , wherein part (c) further comprises attaching a rigid inflexible rod member to the spacing member, and using said rigid inflexible rod member for directing and inserting the spacing member along an arcuate insertion path through the incision such that the imaginary arcuate centerline follows said arcuate insertion path during the insertion.