Artificial disc and joint replacements with modular cushioning components

Abstract

An artificial joint or disc replacement (ADR) broadly includes a pair of opposing endplate components, each attached to one of the upper and lower vertebrae, a cushioning component disposed between the endplate components, and a mechanism for coupling the cushioning component to one or both of the endplates. In the preferred embodiment, the cushioning component takes the form of a tire-like outer structure attached to an inner hub. A filler material is also preferably contained within the cushioning component. The filler material may be a gas, liquid, foam, or gel, including a hydrogel. One or both of the endplate components may include a modified surface to increase adherence to respective opposing bone surfaces.

1 . A modular implant configured for placement between opposing bone surfaces, comprising: 
 at least one endplate component attached to one of the opposing bone surfaces;    a modular cushioning component removably attached to the endplate component; and    a mechanism allowing the cushioning component to be installed, removed or replaced with the endplate component attached.    
   
   
       2 . The implant of  claim 1 , wherein the cushioning component includes a filler material.  
   
   
       3 . The implant of  claim 2 , wherein the filler material is a gas, liquid, foam, gel or hydrogel.  
   
   
       4 . The implant of  claim 1 , wherein the endplate component includes a modified surface to increase adherence to the respective bone surface.  
   
   
       5 . The implant of  claim 4 , wherein the modified surface includes spikes or other projections.  
   
   
       6 . The implant of  claim 4 , wherein the modified surface is conducive to bony ingrowth.  
   
   
       7 . The implant of  claim 1 , wherein: 
 the cushioning component includes an outer, compressible tire-like structure attached to a central hub; and    the central hub includes the mechanism for interlocking the cushioning component to the endplates.    
   
   
       8 . The implant of  claim 7 , wherein the mechanism for interlocking the cushioning component to the endplates includes a projection on the central hub and a corresponding groove on the endplate allowing the implant to be pushed into position.  
   
   
       9 . The implant of  claim 8 , further including a screw or other fastener for maintaining the projection in the groove.  
   
   
       10 . The implant of  claim 8 , wherein the compressible tire-like structure component includes a filler material.  
   
   
       11 . The implant of  claim 10 , wherein the filler material is a gas, liquid, foam, gel or hydrogel.  
   
   
       12 . The implant of  claim 1 , further including a clip or other device for compressing the implant until insertion between the opposing bone surfaces.  
   
   
       13 . The implant of  claim 1 , wherein the component is configured for adherence to a vertebral endplate.  
   
   
       14 . The implant of  claim 1 , wherein: 
 the endplate is configured for adherence to the articular portion of a prosthetic tibia component.    
   
   
       15 .- 25 . (canceled)  
   
   
       26 . A method of inserting an artificial disc replacement (ADR) into an intervertebral disc space, comprising the steps of: 
 inserting a vertebral endplate into a disc space;    affixing the endplate component to a vertebral body; and    inserting a cushioning component into the disc space after the endplate has been affixed.