Prosthetic apparatus and method

Abstract

A prosthetic nucleus for implantation in a chamber of an intervertebral disc after removal of at least a portion of a damaged or degenerated nucleus from the chamber, comprising a wafer of biologically compatible, thin, flexible, and expandable material in a selected first configuration. The wafer is adapted to be re-shaped mechanically into a compact second configuration of cross-section sufficiently small to permit travel of the wafer through a cannula and into the disc chamber. The wafer is further adapted to substantially regain the first configuration thereof by memory upon entry into the disc chamber, and the wafer is adapted to react to an expansion-inducing agent in the disc chamber to expand to an enlarged and selected third configuration.

1 - 22 . (canceled)  
     
     
         23 . A method for implanting a prosthetic nucleus in a chamber of an intervertebral disc after removal of at least a portion of a damaged or degenerated nucleus from the chamber, the method comprising the steps of: 
 providing a prosthetic nucleus comprising a wafer of biologically compatible, thin, flexible, and expandable material in a selected first configuration, said wafer being adapted to be re-shaped mechanically into a compact second configuration of cross-section sufficiently small to permit travel of said wafer through a cannula and into the disc chamber, said wafer being adapted to substantially regain the first configuration thereof by memory upon entry into the disc chamber, said wafer being adapted to react to an expansion-inducing agent in the disc chamber to expand to an enlarged and selected third configuration;    mechanically re-shaping said wafer into the second configuration and placing said wafer in the cannula; and    injecting said wafer into the disc chamber, whereupon said wafer substantially regains the first configuration and, upon contact with the expansion-inducing agent, expands in the disc chamber to the third configuration.    
     
     
         24 . A method for implanting a prosthetic nucleus in a chamber of an intervertebral disc after removal of at least a portion of a damaged or degenerated nucleus from the chamber, the method comprising the steps of: 
 providing a prosthetic nucleus comprising a wafer of biologically compatible and expandable material in a selected first configuration, said wafer being adapted to be collapsed into a compact second configuration of cross-section sufficiently small to permit travel of said wafer through a cannula and into the disc chamber, and said wafer being adapted to react to an expansion-inducing agent in the disc chamber to expand to an enlarged and selected third configuration;    collapsing said wafer into the second configuration and placing said wafer in the cannula;    injecting said wafer into the disc chamber, whereupon said wafer substantially regains the first configuration and makes contact with the expansion-inducing agent and expands in the disc chamber to the third configuration.    
     
     
         25 . A method for implanting a prosthetic nucleus in a chamber of an intervertebral disc after removal of at least a portion of a damaged or degenerated nucleus from the chamber, the method comprising the steps of: 
 providing a prosthetic nucleus comprising a wafer of biologically compatible, thin, flexible, and expandable material in a selected first configuration, said wafer being adapted to be re-shaped mechanically into a compact second configuration of cross-section sufficiently small to permit travel of said wafer through a cannula and into the disc chamber, said wafer being adapted to substantially regain the first configuration thereof by memory upon entry into the disc chamber, and said wafer being adapted to react to an expansion-inducing agent introduced into said wafer to expand to an enlarged and selected third configuration;    mechanically re-shaping said wafer into the second configuration and placing said wafer in the cannula;    injecting said wafer into the disc chamber, whereupon said wafer substantially regains the first configuration thereof; and    injecting the expansion-inducing agent into said wafer to expand said wafer to the third configuration.    
     
     
         26 . A method for implanting a prosthetic nucleus in a chamber of an intervertebral disc after removal of at least a portion of a damaged or degenerated nucleus from the chamber, the method comprising the steps of: 
 providing a prosthetic nucleus comprising a plurality of wafers of biologically compatible and expandable material, each in a selected first configuration, said wafers being adapted to be re-shaped mechanically into a compact second configuration of cross-section sufficiently small to permit travel of said wafers through a cannula and into the disc chamber, said wafers being adapted to substantially regain the first configuration thereof by memory upon entry into the disc chamber, and said wafers being adapted to react to an expansion-inducing agent to expand to an enlarged and selected third configuration;    mechanically re-shaping said wafers into the second configuration and placing said wafers in the cannula; and    injecting said wafers into the disc chamber, whereupon said wafers regain their first configuration and, upon contact with the expansion-inducing agent, expand to the third configuration.    
     
     
         27 . A method according to  claim 23  wherein a tool is used to assist said wafer in substantially regaining the first configuration.  
     
     
         28 . A method for implanting a prosthetic nucleus in a chamber of an intervertebral disc after removal of at least a portion of a damaged or degenerated nucleus from the chamber, the method comprising the steps of: 
 providing a prosthetic nucleus comprising a wafer of biologically compatible, thin, flexible, and expandable material initially in a selected first configuration, said wafer being adapted to be re-shaped mechanically into a compact second configuration of cross-section sufficiently small to permit travel of said wafer through a cannula and into the disc chamber said wafer being adapted to substantially regain the first configuration thereof by memory upon entry into the disc chamber, said wafer being adapted to react to an expansion-inducing agent in the disc chamber to expand to an enlarged and selected third configuration, with said wafer having been mechanically re-shaped into the second configuration and placed in the cannula; and    injecting said wafer into the disc chamber, whereupon said wafer substantially regains the first configuration and, upon contact with the expansion-inducing agent, expands in the disc chamber to the third configuration.    
     
     
         29 . A method for implanting a prosthetic intervertebral nucleus into an intervertebral disc space, comprising: 
 providing an implant configured for transitioning between a first substantially planar configuration and a second non-planar configuration;    reconfiguring the implant from the first substantially planar configuration into the second non-planar configuration; and    inserting the implant into the disc space while in the second non-planar configuration, the implant substantially regaining the first substantially planar configuration subsequent to entry into the disc space.    
     
     
         30 . The method of  claim 29 , further comprising expanding the implant within the disc space from the first substantially planar configuration to a third expanded configuration.  
     
     
         31 . The method of  claim 30 , wherein the implant has a first thickness substantially less than a height of the disc space when in the first substantially planar configuration, the implant having a second thickness approximately equal to the height of the disc space when expanded to the third expanded configuration.  
     
     
         32 . The method of  claim 30 , wherein the expanding of the implant results from reaction to an expansion-inducing agent.  
     
     
         33 . The method of  claim 30 , wherein the expanding of the implant results from changing a temperature of the implant.  
     
     
         34 . The method of  claim 30 , wherein the expanding of the implant results from introducing an expansion-inducing agent into the implant.  
     
     
         35 . The method of  claim 30 , wherein the expanding of the implant results from introducing an expansion-inducing agent into the disc space.  
     
     
         36 . The method of  claim 29 , wherein the reconfiguring comprises collapsing the implant into a reduced cross section.  
     
     
         37 . The method of  claim 29 , wherein the reconfiguring comprises rolling the implant into the second non-planar configuration.  
     
     
         38 . The method of  claim 29 , wherein the reconfiguring comprises curling the implant into the second non-planar configuration.  
     
     
         39 . The method of  claim 29 , wherein the reconfiguring comprises folding the implant into the second non-planar configuration.  
     
     
         40 . The method of  claim 29 , wherein the substantially regaining comprises at least one of unrolling, uncurling and unfolding the implant from the second non-planar configuration toward the first substantially planar configuration.  
     
     
         41 . The method of  claim 29 , wherein the implant substantially regains the first substantially planar configuration by memory subsequent to entry into the disc space.  
     
     
         42 . The method of  claim 29 , wherein the inserting comprises positioning the reconfigured implant into a cannula and advancing the implant through the cannula and into the disc space.  
     
     
         43 . The method of  claim 42 , further comprising inserting a distal end portion of the cannula through an opening in the disc annulus and into the disc space for delivery of the implant the disc space.  
     
     
         44 . The method of  claim 29 , wherein the implant comprises a wafer of biologically compatible material.  
     
     
         45 . The method of  claim 44 , wherein the wafer of material is expanded within the disc space in response to an expansion-inducing agent.  
     
     
         46 . The method of  claim 44 , wherein the wafer of material is thin and flexible.  
     
     
         47 . The method of  claim 29 , wherein the implant comprises a plurality of implant portions configured for transitioning between the first substantially planar configuration and the second non-planar configuration.  
     
     
         48 . The method of  claim 47 , further comprising stacking the plurality of implant portions within the disc space.  
     
     
         49 . The method of  claim 29 , wherein the inserting comprises passing the implant through an opening in the disc annulus and into the disc space.  
     
     
         50 . A method for implanting a prosthetic intervertebral nucleus into an intervertebral disc space, comprising: 
 providing an implant configured for transitioning between a first configuration and a second configuration, the second configuration having a reduced cross section relative to the first configuration;    reconfiguring the implant from the first configuration into the second configuration;    inserting the implant into the disc space while in the second configuration, the implant substantially regaining the first configuration subsequent to entry into the disc space; and    expanding the implant to a third expanded configuration within the disc space in response to an expansion-inducing agent.    
     
     
         51 . The method of  claim 50 , wherein the implant has a first thickness substantially less than a height of the disc space when in the first configuration, the implant having a second thickness approximately equal to the height of the disc space when expanded to the third expanded configuration.  
     
     
         52 . The method of  claim 50 , wherein the reconfiguring comprises collapsing the implant into the reduced cross section.  
     
     
         53 . The method of  claim 50 , wherein the reconfiguring comprises at least one of rolling, curling and folding the implant into the reduced cross section.  
     
     
         54 . The method of  claim 50 , wherein the substantially regaining comprises at least one of unrolling, uncurling and unfolding the implant from the second configuration back toward the first configuration.  
     
     
         55 . A method for implanting a prosthetic intervertebral nucleus into an intervertebral disc space, comprising: 
 providing an implant configured for transitioning between a first substantially planar shape and a second non-planar shape;    mechanically reshaping the implant from the first substantially planar shape to the second non-planar shape; and    inserting the implant into the disc space while in the second non-planar shape, the implant substantially regaining the first substantially planar shape subsequent to entry into the disc space.    
     
     
         56 . The method of  claim 55 , further comprising expanding the implant within the disc space from the first substantially planar shape to a third expanded shape, the implant having a first thickness substantially less than a height of the disc space when in the first substantially planar shape, the implant having a second thickness approximately equal to the height of the disc space when expanded to the third expanded shape.  
     
     
         57 . The method of  claim 55 , wherein the mechanically reshaping comprises collapsing the implant into a reduced cross section.  
     
     
         58 . The method of  claim 55 , wherein the mechanically reshaping comprises at least one of rolling, curling and folding the implant into the second non-planar shape.  
     
     
         59 . The method of  claim 55 , wherein the substantially regaining comprises at least one of unrolling, uncurling and unfolding the implant from the second non-planar shape toward the first substantially planar shape.  
     
     
         60 . The method of  claim 55 , wherein the inserting comprises positioning the mechanically reshaped implant into a cannula and advancing the implant through the cannula and into the disc space.  
     
     
         61 . The method of  claim 60 , further comprising inserting a distal end portion of the cannula through an opening in the disc annulus and into the disc space for delivery of the implant the disc space.