Facet joint replacement

Abstract

A prosthesis for the replacement of at least a portion of the bone of a facet located on a mammalian vertebra, comprising: an articulating surface that articulates with another facet; a bone contacting surface that contacts a surface of the vertebra, the articulating surface being connected to the bone contacting surface; and a fixation element that attaches the bone contacting surface to the vertebra, the fixation element being adapted for implantation into an interior bone space of a pedicle of the vertebra; wherein the prosthesis is configured so that no portion of the prosthesis contacts the posterior arch of the vertebra.

1 . A prosthesis for the replacement of at least a portion of the bone of a facet located on a mammalian vertebra, comprising: 
 an articulating surface that articulates with another facet;    a bone contacting surface that contacts a surface of the vertebra, said articulating surface being connected to said bone contacting surface; and    a fixation element that attaches said bone contacting surface to the vertebra, said fixation element being adapted for implantation into an interior bone space of a pedicle of the vertebra;    wherein said prosthesis is configured so that no portion of said prosthesis contacts the posterior arch of said vertebra.    
     
     
         2 . A prosthesis according to  claim 1  wherein the surface of said vertebra contacted by said bone contacting surface comprises an exterior surface of the vertebra.  
     
     
         3 . A prosthesis according to  claim 1  wherein the surface of the vertebra contacted by said bone contacting surface comprises a resected surface of said vertebra.  
     
     
         4 . A prosthesis according to  claim 1  wherein said fixation element comprises a post, said bone contacting surface defines an opening therein, and further wherein said post attaches said bone contacting surface to the vertebra by extending through said opening.  
     
     
         5 . A prosthesis according to  claim 4  wherein said fixation element comprises an enlarged head attached to said post for capturing said bone contacting surface against the surface of the vertebra.  
     
     
         6 . A prosthesis according to  claim 5  wherein said enlarged head is permanently attached to said post.  
     
     
         7 . A prosthesis according to  claim 5  wherein said enlarged head is selectively attachable to said post.  
     
     
         8 . A prosthesis according to  claim 7  wherein said post is threaded at its outer end, and further wherein said enlarged head comprises a nut adapted to be selectively screwed onto said threaded post.  
     
     
         9 . A prosthesis according to  claim 4  wherein said post comprises a non-circular recess on its outer end for turning said post into the vertebra.  
     
     
         10 . A prosthesis according to  claim 9  wherein said non-circular recess comprises a hexagonal cross-section.  
     
     
         11 . A prosthesis according to  claim 4  wherein said post is cannulated to facilitate delivery to the vertebra over a guidewire.  
     
     
         12 . A prosthesis according to  claim 4  wherein said post is threaded on its inner end to facilitate attachment to the vertebra.  
     
     
         13 . A prosthesis according to  claim 4  wherein said post is ribbed on its inner end to facilitate attachment to the vertebra.  
     
     
         14 . A prosthesis according to  claim 13  wherein said ribbing extends parallel to the longitudinal axis of said post.  
     
     
         15 . A prosthesis according to  claim 13  wherein said ribbing extends transverse to the longitudinal axis of said post.  
     
     
         16 . A prosthesis according to  claim 4  wherein said post is barbed on its inner end to facilitate attachment to the vertebra.  
     
     
         17 . A prosthesis according to  claim 4  wherein said post has a circular cross-section along at least a portion of its length.  
     
     
         18 . A prosthesis according to  claim 4  wherein said post has a non-circular cross-section along at least a portion of its length.  
     
     
         19 . A prosthesis according to  claim 18  wherein said post has an oval cross-section along at least a portion of its length.  
     
     
         20 . A prosthesis according to  claim 18  wherein said post has a polygonal cross-section along at least a portion of its length.  
     
     
         21 . A prosthesis according to  claim 20  wherein said post has a rectangular cross-section along at least a portion of its length.  
     
     
         22 . A prosthesis according to  claim 20  wherein said post has a triangular cross-section along at least a portion of its length.  
     
     
         23 . A prosthesis according to  claim 4  wherein said post has an expandable cross-section along at least a portion of its length.  
     
     
         24 . A prosthesis according to  claim 23  wherein said post comprises an inner member and an outer member, said inner member is slidably received within said outer member, and further wherein said outer member expands relative to said member according to the longitudinal position of said inner member relative to said outer member.  
     
     
         25 . A prosthesis according to  claim 24  wherein said outer member comprises a plurality of talons which are cammed outward by said inner member depending on the longitudinal position of said inner member relative to said outer member.  
     
     
         26 . A prosthesis according to  claim 4  wherein said prosthesis further comprises a supplemental holding element for holding said fixation element to said vertebra.  
     
     
         27 . A prosthesis according to  claim 26  wherein said supplemental holding element comprises a transverse pin, and further wherein said post comprises a transverse hole for receiving said transverse pin.  
     
     
         28 . A prosthesis according to  claim 26  wherein said supplemental holding element comprises a spiked washer, said fixation element comprises an enlarged head for capturing said bone contacting surface against the surface of the vertebra, and further wherein said spiked washer is captured to said vertebra by said enlarged head.  
     
     
         29 . A prosthesis according to  claim 26  wherein said supplemental holding element comprises a filament extending through a filament opening formed in said fixation element.  
     
     
         30 . A prosthesis according to  claim 29  wherein said filament opening is formed in said post.  
     
     
         31 . A prosthesis according to  claim 29  wherein said fixation element comprises an enlarged head for capturing said bone contacting surface against the surface of the vertebra, and further wherein said filament opening is formed in said enlarged head.  
     
     
         32 . A prosthesis according to  claim 1  wherein said prosthesis comprises a superior facet prosthesis.  
     
     
         33 . A prosthesis according to  claim 32  wherein said articulating surface comprises a blade.  
     
     
         34 . A prosthesis according to  claim 4  wherein said articulating surface comprises a blade, and further wherein said blade is laterally offset from said opening.  
     
     
         35 . A prosthesis according to  claim 1  wherein said prosthesis comprises an inferior facet prosthesis.  
     
     
         36 . A prosthesis according to  claim 35  wherein said articulating surface comprises a talon.  
     
     
         37 . A prosthesis according to  claim 4  wherein said articulating surface comprises a talon, and further wherein at least a portion of said talon is laterally offset from said opening.  
     
     
         38 . A prosthesis for the replacement of at least a portion of the bone of a facet located on a mammalian vertebra, comprising: 
 an articulating surface that articulates with another facet;    a bone contacting surface that contacts a surface of the vertebra, said articulating surface being connected to said bone contacting surface; and    a fixation element that attaches said bone contacting surface to the vertebra, said fixation element being adapted for implantation into an interior bone space of a pedicle of the vertebra;    wherein said bone contacting surface is configured to engage a resected surface of the vertebra.    
     
     
         39 . A prosthesis according to  claim 38  wherein the resected surface of the vertebra is recessed relative to the surrounding portions of the vertebra, and further wherein said bone contacting surface is configured to engage the recessed surface.  
     
     
         40 . A prosthesis for the replacement of at least a portion of the bone of a facet located on a mammalian vertebra, comprising: 
 an articulating surface that articulates with another facet;    a bone contacting surface that contacts a surface of the vertebra, said articulating surface being connected to said bone contacting surface; and    a fixation element that attaches said bone contacting surface to the vertebra, said fixation element being adapted for implantation into an interior bone space of a pedicle of the vertebra;    wherein said bone contacting surface has a smaller surface area than said articulating surface.    
     
     
         41 . A prosthesis for the replacement of at least a portion of the bone of a facet located on a mammalian vertebra, comprising: 
 an articulating surface that articulates with another facet;    a bone contacting surface that contacts a surface of the vertebra, said articulating surface being connected to said bone contacting surface; and    a fixation element that attaches said bone contacting surface to the vertebra, said fixation element being adapted for implantation into an interior bone space of a pedicle of the vertebra;    wherein said articulating surface comprises a wing ear extending upward from said bone contacting surface.    
     
     
         42 . A prosthesis for the replacement of at least a portion of the bone of a facet located on a mammalian vertebra, comprising: 
 an articulating surface that articulates with another facet;    a bone contacting surface that contacts a surface of the vertebra, said articulating surface being connected to said bone contacting surface; and    a fixation element that attaches said bone contacting surface to the vertebra, said fixation element being adapted for implantation into an interior bone space of a pedicle of the vertebra;    wherein said articulating surface is substantially planar and extends adjacent to the pedicle.    
     
     
         43 . A prosthesis for the replacement of at least a portion of the bone of a facet located on a mammalian vertebra, comprising: 
 an articulating surface that articulates with another facet;    a bone contacting surface that contacts a surface of the vertebra, said articulating surface being connected to said bone contacting surface; and    a fixation element that attaches said bone contacting surface to the vertebra, said fixation element being adapted for implantation into an interior bone space of a pedicle of the vertebra;    wherein said articulating surface is substantially planar and extends substantially parallel to said fixation element.    
     
     
         44 . A prosthesis for the replacement of at least a portion of the bone of a facet located on a mammalian vertebra, comprising: 
 an articulating surface that articulates with another facet;    a bone contacting surface that contacts a surface of the vertebra, said articulating surface being connected to said bone contacting surface; and    a fixation element that attaches said bone contacting surface to the vertebra, said fixation element being adapted for implantation into an interior bone space of a pedicle of the vertebra;    wherein said fixation element clamps said bone contacting surface to a resected surface of the vertebra.    
     
     
         45 . A prosthesis for the replacement of at least a portion of the bone of a facet located on a mammalian vertebra, comprising: 
 an articulating element that articulates with another facet;    a bone contacting element that contacts a surface of the vertebra, said articulating element being connected to said bone contacting element; and    a fixation element that attaches said bone contacting element to the vertebra, said fixation element being adapted for implantation into an interior bone space of a pedicle of the vertebra;    wherein said prosthesis is configured so that no portion of said prosthesis contacts the posterior arch of said vertebra.    
     
     
         46 . A prosthesis for the replacement of at least a portion of the bone of a superior facet located on a mammalian vertebra and for replacement of at least a portion of the bone of an inferior facet located on the same mammalian vertebra, comprising: 
 a superior articulating element that articulates with another facet;    a superior bone contacting element that contacts one of a surface of the vertebra or another element contacting a surface of the vertebra, said superior articulating element being connected to said superior bone contacting element; and    an inferior articulating element that articulates with another facet;    an inferior bone contacting element that contacts one of a surface of the vertebra or another element contacting a surface of the vertebra, said inferior articulating element being connected to said inferior bone contacting element; and    a fixation element that attaches said superior bone contacting element and said inferior bone contacting element to the vertebra, said fixation element being adapted for implantation into an interior bone space of a pedicle of the vertebra;    wherein said prosthesis is configured so that no portion of said prosthesis contacts the posterior arch of said vertebra.    
     
     
         47 . A prosthesis for the replacement of at least a portion of the bone of a superior facet located on a first mammalian vertebra and for replacement of at least a portion of the bone of an inferior facet located on a second mammalian vertebra, comprising: 
 a superior articulating element that articulates with another facet;    a superior bone contacting element that contacts one of a surface of the first vertebra or another element contacting a surface of the vertebra, said superior articulating element being connected to said superior bone contacting element;    a first fixation element that attaches said superior bone contacting element to the first vertebra, said first fixation element being adapted for implantation into an interior bone space of a pedicle of the vertebra; and    an inferior articulating element that articulates with another facet;    an inferior bone contacting element that contacts one of a surface of the second vertebra or another element contacting a surface of the vertebra, said inferior articulating element being connected to said inferior bone contacting element; and    a second fixation element that attaches said inferior bone contacting element to the second vertebra, said second fixation element being adapted for implantation into an interior bone space of a pedicle of the vertebra; and    wherein said prosthesis is configured so that no portion of said prosthesis contacts the posterior arches of said first and second vertebrae.    
     
     
         48 . A method for replacing at least a portion of the bone of a facet located on a mammalian vertebra, comprising: 
 providing: 
 an articulating surface that articulates with another facet;  
 a bone contacting surface that contacts a surface of the vertebra, said articulating surface being connected to said bone contacting surface; and  
 a fixation element that attaches said bone contacting surface to the vertebra, said fixation element being adapted for implantation into an interior bone space of a pedicle of the vertebra;  
 wherein said prosthesis is configured so that no portion of said prosthesis contacts the posterior arch of said vertebra; and  
   positioning said bone contacting surface against a surface of the vertebra; and    attaching said bone contacting surface to the vertebra using said fixation element.    
     
     
         49 . A method according to  claim 48  wherein the surface of said vertebra contacted by said bone contacting surface comprises an exterior surface of the vertebra.  
     
     
         50 . A method according to  claim 48  wherein the surface of the vertebra contacted by said bone contacting surface comprises a resected surface of said vertebra.  
     
     
         51 . A method according to  claim 48  wherein said fixation element comprises a post, said bone contacting surface defines an opening therein, and further wherein said post attaches said bone contacting surface to the vertebra by extending through said opening.  
     
     
         52 . A method according to  claim 51  wherein said fixation element comprises an enlarged head attached to said post for capturing said bone contacting surface against the surface of the vertebra.  
     
     
         53 . A method according to  claim 52  wherein said enlarged head is permanently attached to said post.  
     
     
         54 . A method according to  claim 52  wherein said enlarged head is selectively attachable to said post.  
     
     
         55 . A method according to  claim 54  wherein said post is threaded at its outer end, and further wherein said enlarged head comprises a nut adapted to be selectively screwed onto said threaded post.  
     
     
         56 . A method according to  claim 51  wherein said post comprises a non-circular recess on its outer end for turning said post into the vertebra.  
     
     
         57 . A method according to  claim 56  wherein said non-circular recess comprises a hexagonal cross-section.  
     
     
         58 . A method according to  claim 51  wherein said post is cannulated to facilitate delivery to the vertebra over a guidewire.  
     
     
         59 . A method according to  claim 51  wherein said post is threaded on its inner end to facilitate attachment to the vertebra.  
     
     
         60 . A method according to  claim 51  wherein said post is ribbed on its inner end to facilitate attachment to the vertebra.  
     
     
         61 . A method according to  claim 60  wherein said ribbing extends parallel to the longitudinal axis of said post.  
     
     
         62 . A method according to  claim 60  wherein said ribbing extends transverse to the longitudinal axis of said post.  
     
     
         63 . A method according to  claim 51  wherein said post is barbed on its inner end to facilitate attachment to the vertebra.  
     
     
         64 . A method according to  claim 51  wherein said post has a circular cross-section along at least a portion of its length.  
     
     
         65 . A method according to  claim 51  wherein said post has a non-circular cross-section along at least a portion of its length.  
     
     
         66 . A method according to  claim 65  wherein said post has an oval cross-section along at least a portion of its length.  
     
     
         67 . A method according to  claim 65  wherein said post has a polygonal cross-section along at least a portion of its length.  
     
     
         68 . A method according to  claim 67  wherein said post has a rectangular cross-section along at least a portion of its length.  
     
     
         69 . A method according to  claim 67  wherein said post has a triangular cross-section along at least a portion of its length.  
     
     
         70 . A method according to  claim 51  wherein said post has an expandable cross-section along at least a portion of its length.  
     
     
         71 . A method according to  claim 70  wherein said post comprises an inner member and an outer member, said inner member is slidably received within said outer member, and further wherein said outer member expands relative to said inner member according to the longitudinal position of said inner member relative to said outer member.  
     
     
         72 . A method according to  claim 71  wherein said outer member comprises a plurality of talons which are cammed outward by said inner member depending on the longitudinal position of said inner member relative to said outer member.  
     
     
         73 . A method according to  claim 51  wherein said prosthesis further comprises a supplemental holding element for holding said fixation element to said vertebra.  
     
     
         74 . A method according to  claim 73  wherein said supplemental holding element comprises a transverse pin, and further wherein said post comprises a transverse hole for receiving said transverse pin.  
     
     
         75 . A method according to  claim 73  wherein said supplemental holding element comprises a spiked washer, said fixation element comprises an enlarged head for capturing said bone contacting surface against the surface of the vertebra, and further wherein said spiked washer is captured to said vertebra by said enlarged head.  
     
     
         76 . A method according to  claim 73  wherein said supplemental holding element comprises a filament extending through a filament opening formed in said fixation element.  
     
     
         77 . A method according to  claim 76  wherein said filament opening is formed in said post.  
     
     
         78 . A method according to  claim 76  wherein said fixation element comprises an enlarged head for capturing said bone contacting surface against the surface of the vertebra, and further wherein said filament opening is formed in said enlarged head.  
     
     
         79 . A method according to  claim 48  wherein said prosthesis comprises a superior facet prosthesis.  
     
     
         80 . A method according to  claim 79  wherein said articulating surface comprises a blade.  
     
     
         81 . A method according to  claim 51  wherein said articulating surface comprises a blade, and further wherein said blade is laterally offset from said opening.  
     
     
         82 . A method according to  claim 51  wherein said prosthesis comprises an inferior facet prosthesis.  
     
     
         83 . A method according to  claim 82  wherein said articulating surface comprises a finger.  
     
     
         84 . A method according to  claim 51  wherein said articulating surface comprises a finger, and further wherein at least a portion of said finger is laterally offset from said opening.  
     
     
         85 . A prosthesis for the replacement of at least a portion of the bone of a facet located on a mammalian vertebra, comprising: 
 an articulating element that articulates with another facet;    a bone contacting element that contacts a surface of the vertebra or another element contacting a surface of the vertebra, said articulating element being connected to said bone contacting element; and    a fixation element that attaches said bone contacting element to the vertebra, said fixation element being adapted for implantation into an interior bone space of a pedicle of the vertebra;    wherein said prosthesis is configured so that no portion of said prosthesis contacts the posterior arch of said vertebra.    
     
     
         86 . A prosthesis according to  claim 85  wherein said prosthesis comprises a superior facet prosthesis.  
     
     
         87 . A prosthesis according to  claim 86  wherein said bone contacting element is adapted to contact a resected surface of a pedicle or another element contacting a resected surface of a pedicle.  
     
     
         88 . A prosthesis according to  claim 85  wherein said articulating element comprises a blade.  
     
     
         89 . A prosthesis according to  claim 85  wherein said prosthesis comprises an inferior facet prosthesis.  
     
     
         90 . A prosthesis according to  claim 89  wherein said bone contacting element is adapted to contact a resected surface of a pedicle or another element contacting a resected surface of a pedicle.  
     
     
         91 . A prosthesis according to  claim 89  wherein said articulating element comprises a finger.  
     
     
         92 . A prosthesis according to  claim 91  wherein said articulating element is configured to engage a resected surface of an inferior facet.  
     
     
         93 . A prosthesis according to  claim 89  wherein at least a portion of said finger is laterally offset from said bone contacting element.  
     
     
         94 . A method for replacing at least a portion of the bone of a facet located on a mammalian vertebra, comprising: 
 an articulating element that articulates with another facet;    a bone contacting element that contacts a surface of the vertebra or another element contacting a surface of the vertebra, said articulating element being connected to said bone contacting element; and    a fixation element that attaches said bone contacting element to the vertebra, said fixation element being adapted for implantation into an interior bone space of a pedicle of the vertebra;    wherein said prosthesis is configured so that no portion of said prosthesis contacts the posterior arch of said vertebra;    positioning said bone contacting surface against a surface of the vertebra or another element contacting a surface of the vertebra; and    attaching said bone contacting surface to the vertebra using said fixation element.    
     
     
         95 . A method according to  claim 85  wherein said prosthesis comprises a superior facet prosthesis.  
     
     
         96 . A method according to  claim 95  wherein said bone contacting element is adapted to contact a resected surface of a pedicle or another element contacting a resected surface of a pedicle.  
     
     
         97 . A method according to  claim 94  wherein said articulating element comprises a blade.  
     
     
         98 . A method according to  claim 94  wherein said prosthesis comprises an inferior facet prosthesis.  
     
     
         99 . A method according to  claim 98  wherein said bone contacting element is adapted to contact a resected surface of a pedicle or another element contacting a resected surface of a pedicle.  
     
     
         100 . A method according to  claim 98  wherein said articulating element comprises a finger.  
     
     
         101 . A method according to  claim 100  wherein said articulating element is configured to engage a resected surface of an inferior facet.  
     
     
         102 . A method according to  claim 98  wherein at least a portion of said finger is laterally offset from said bone contacting element.