Facet arthroplasty devices and methods

Abstract

Devices and surgical methods treat various types of adult spinal pathologies, such as degenerative spondylolisthesis, spinal stenosis, degenerative lumbar scoliosis, and kypho-scoliosis. Various types of spinal joint replacement prostheses, surgical procedures for performing spinal joint replacements, and surgical instruments are used to perform the surgical procedures.

1 . A system for replacing at least a portion of a natural facet of a first vertebra, the system comprising: a first prosthesis comprising: 
 a first facet articular surface shaped to articulate with a second facet articular surface on a second vertebra; and an engagement member connected to the first facet articular surface, wherein the engagement member is shaped to engage the first vertebra to secure the first facet articular surface with respect to the first vertebra independently of attachment of the first facet articular surface to either of two pedicles of the first vertebra and independently of attachment of the first facet articular surface to a spinous process of the first vertebra.    
     
     
         2 . The system of  claim 1 , wherein the engagement member is shaped to penetrate a lamina of the first vertebra to secure the first facet articular surface to the lamina.  
     
     
         3 . The system of  claim 1 , wherein the first facet articular surface is shaped to replace a natural inferior facet articular surface of the first vertebra.  
     
     
         4 . The system of  claim 1 , further comprising a second prosthesis comprising the second facet articular surface, wherein the second prosthesis cooperates with the first prosthesis to provide a first prosthetic facet joint to control relative motion between the first and second vertebrae.  
     
     
         5 . The system of  claim 4 , further comprising a third prosthesis and a fourth prosthesis configured to cooperate with each other to provide a second prosthetic facet joint attachable to the first and second vertebrae to further control relative motion between the first and second vertebrae.  
     
     
         6 . A system for replacing at least a portion of a natural facet of a first vertebra, the system comprising: a first prosthesis comprising: 
 a first facet articular surface shaped to articulate with a second facet articular surface on a second vertebra; and an engagement member connected to the first facet articular surface,    wherein the engagement member is shaped to engage a lamina of the first vertebra to independently secure the first facet articular surface with respect to the first vertebra.    
     
     
         7 . The system of  claim 6 , wherein the engagement member comprises a fin extending from the facet articular surface.  
     
     
         8 . The system of  claim 6 , wherein the engagement member is shaped to leave the lamina substantially intact after penetration of the lamina by the engagement member.  
     
     
         9 . The system of  claim 6 , wherein the engagement member is shaped to secure the first facet articular surface with respect to the first vertebra independently of contact between the first prosthesis and any portion of the first vertebra besides the lamina.  
     
     
         10 . The system of  claim 6 , wherein the first facet articular surface is shaped to replace a natural inferior facet articular surface of the first vertebra.  
     
     
         11 . The system of  claim 6 , further comprising a second prosthesis comprising the second facet articular surface, wherein the second prosthesis cooperates with the first prosthesis to provide a first prosthetic facet joint to control relative motion between the first and second vertebrae.  
     
     
         12 . The system of  claim 11 , further comprising a third prosthesis and a fourth prosthesis configured to cooperate with each other to provide a second prosthetic facet joint attachable to the first and second vertebrae to further control relative motion between the first and second vertebrae.  
     
     
         13 . A method for replacing at least a portion of a natural facet of a first vertebra, the method comprising: positioning a first facet articular surface of a first prosthesis to articulate with a second facet articular surface on a second vertebra; and engaging the first vertebra with the first prosthesis to secure the first facet articular surface with respect to the first vertebra independently of attachment of the first facet articular surface to either of two pedicles of the vertebra and independently of attachment of the first facet articular surface to a spinous process of the first vertebra.  
     
     
         14 . The method of  claim 13 , wherein engaging the first vertebra with the first prosthesis comprises penetrating a lamina of the first vertebra to secure the first facet articular surface to the lamina.  
     
     
         15 . The method of  claim 13 , wherein positioning the first facet articular surface to articulate with the second facet articular surface comprises positioning the first facet articular surface to replace a natural inferior facet articular surface of the first vertebra.  
     
     
         16 . A method for replacing at least a portion of a natural facet of a first vertebra, the method comprising: positioning a first facet articular surface of a first prosthesis to articulate with a second facet articular surface on a second vertebra; and engaging a lamina of the first vertebra with an engagement member of the first prosthesis to independently secure the first facet articular surface to the first vertebra, wherein the engagement member is connected to the first facet articular surface.  
     
     
         17 . The method of  claim 16 , wherein the engagement member comprises a fin extending from the facet articular surface, wherein penetrating the lamina with the engagement member comprises inserting the fin into an interior bone space of the lamina.  
     
     
         18 . The method of  claim 16 , wherein penetrating the lamina with the engagement member comprises leaving the lamina substantially intact.  
     
     
         19 . The method of  claim 16 , wherein penetrating the lamina with the engagement member comprises securing the first facet articular surface with respect to the first vertebra independently of contact between the first prosthesis and any portion of the first vertebra besides the lamina.  
     
     
         20 . The method of  claim 16 , wherein positioning the first facet articular surface to articulate with the second facet articular surface comprises positioning the first facet articular surface to replace a natural inferior facet articular surface of the first vertebra.  
     
     
         21 . A system for replacing at least a portion of a natural facet of a first vertebra, the system comprising: a first prosthesis comprising: 
 a first facet articular surface shaped to articulate with a second facet articular surface on a second vertebra; and an engagement member connected to the first facet articular surface, wherein the engagement member is shaped to penetrate a portion of a lamina of the vertebra to secure the first facet articular surface with respect to the first vertebra such that the first prosthesis does not cover a majority of a posterior aspect of the lamina.    
     
     
         22 . The system of  claim 21 , wherein the engagement member comprises a fin extending from the facet articular surface.  
     
     
         23 . The system of  claim 21 , wherein the engagement member is shaped to leave the lamina substantially intact after penetration of the lamina by the engagement member.  
     
     
         24 . The system of  claim 21 , wherein the engagement member is shaped to secure the first facet articular surface with respect to the first vertebra independently of contact between the first prosthesis and any portion of the first vertebra besides the lamina.  
     
     
         25 . The system of  claim 21 , wherein the first facet articular surface is shaped to replace a natural inferior facet articular surface of the first vertebra.  
     
     
         26 . A system for replacing at least a portion of a natural facet of a first vertebra, the system comprising: a first prosthesis comprising: 
 a first facet articular surface shaped to articulate with a second facet articular surface on a second vertebra; and an engagement member connected to the first facet articular surface, wherein the engagement member is shaped to engage the first vertebra to secure the first facet articular surface with respect to the first vertebra independently of attachment of the first facet articular surface to either of two pedicles of the first vertebra and independently of attachment of the first facet articular surface to either of two transverse processes of the first vertebra.    
     
     
         27 . The system of  claim 26 , wherein the engagement member is shaped to penetrate a lamina of the first vertebra to secure the first facet articular surface to the lamina.  
     
     
         28 . The system of  claim 26 , wherein the first facet articular surface is shaped to replace a natural inferior facet articular surface of the first vertebra.  
     
     
         29 . The system of  claim 26 , further comprising a second prosthesis comprising the second facet articular surface, wherein the second prosthesis cooperates with the first prosthesis to provide a first prosthetic facet joint to control relative motion between the first and second vertebrae.  
     
     
         30 . The system of  claim 29 , further comprising a third prosthesis and a fourth prosthesis configured to cooperate with each other to provide a second prosthetic facet joint attachable to the first and second vertebrae to further control relative motion between the first and second vertebrae.  
     
     
         31 . A method for replacing at least a portion of a natural facet of a first vertebra, the method comprising: positioning a first facet articular surface of a first prosthesis to articulate with a second facet articular surface on a second vertebra; and engaging the first vertebra with the first prosthesis to secure the first facet articular surface with respect to the first vertebra independently of attachment of the first facet articular surface to either of two pedicles of the vertebra and independently of attachment of the first facet articular surface to either of two transverse processes of the first vertebra.  
     
     
         32 . The method of  claim 31 , wherein engaging the first vertebra with the first prosthesis comprises penetrating a lamina of the first vertebra to secure the first facet articular surface to the lamina.  
     
     
         33 . The method of  claim 31 , wherein positioning the first facet articular surface to articulate with the second facet articular surface comprises positioning the first facet articular surface to replace a natural inferior facet articular surface of the first vertebra.