Facet Joint Replacement

Abstract

A prosthesis for the replacement of a diseased or traumatized facet of a mammalian vertebra includes a surface that articulates with another prosthetic facet or a natural facet, a portion that replaces at least a bony portion of the diseased or traumatized spine facet which is to be replaced, and an element to attach the prosthesis to the vertebra in a manner that does not require attachment to or abutment against the posterior arch. A method of installing the prosthesis includes the steps of resecting at least a portion of a facet and attaching the prosthesis in a manner that does not require attachment or abutment against the posterior arch.

What is claimed is: 
     
         1 . A method of replacing a portion of a spine comprising:
 resecting a portion of the spine adjacent a posterior arch;   providing an implant adjacent to the spine, wherein the implant comprises a fin; and   press fitting the fin of the implant into an anterior bone space of the posterior arch.   
     
     
         2 . The method of  claim 1 , wherein the implant comprises a prosthetic inferior facet. 
     
     
         3 . The method of  claim 2 , wherein the prosthetic inferior facet includes an articulating surface. 
     
     
         4 . The method of  claim 1 , wherein the fin is coated with a porous coating to promote bone ingrowth. 
     
     
         5 . The method of  claim 4 , wherein the coating may carry an osteoinductive agent. 
     
     
         6 . The method of  claim 5 , wherein the osteoinductive agent comprises hydroxylapatite, calcium sulfate, or demineralized bone matrix. 
     
     
         7 . The method of  claim 1 , further comprising using a broach or punch to prepare a space for the fin within the posterior arch. 
     
     
         8 . A method of replacing a portion of spine comprising:
 resecting a portion of the spine adjacent a posterior arch;   punching a space in the posterior arch to accommodate an implant; and   press-fitting an implant in the space in the posterior arch.   
     
     
         9 . The method of  claim 8 , wherein the implant comprises a fin. 
     
     
         10 . The method of  claim 8 , wherein the implant comprises a prosthetic inferior facet. 
     
     
         11 . The method of  claim 10 , wherein the prosthetic inferior facet comprises an articulating surface. 
     
     
         12 . The method of  claim 8 , wherein the implant is coated with a porous coating. 
     
     
         13 . The method of  claim 12 , wherein the coating comprises hydroxylapatite, calcium sulfate, or demineralized bone matrix. 
     
     
         14 . A method of replacing a portion of spine comprising:
 resecting a portion of the spine adjacent a pedicle;   providing an implant adjacent the spine, wherein the implant comprises a post; and   creating a space within the pedicle; and   inserting the post of the implant into the space of the pedicle.   
     
     
         15 . The method of  claim 14 , wherein the implant comprises a prosthetic superior facet. 
     
     
         16 . The method of  claim 14 , wherein creating a space within the pedicle is by using a broach or a punch. 
     
     
         17 . The method of  claim 14 , wherein the implant is coated with a porous coating. 
     
     
         18 . The method of  claim 17 , wherein the coating comprises hydroxylapatite, calcium sulfate, or demineralized bone matrix. 
     
     
         19 . The method of  claim 14 , wherein the implant comprises an articulatable surface. 
     
     
         20 . The method of  claim 19 , wherein the implant is configured to articulate with an inferior implant comprising a fin.