Spinal Prosthetic Joints

Abstract

A method for correcting spondylolisthesis from the lateral approach is provided in which a pair of insertion members are inserted laterally into upper and lower vertebrae, a connecting member is affixed to the insertion members, and a rotating force is applied to the connecting member to encourage the upper and lower vertebrae into a desired position relative to one another.

1 - 21 . (canceled) 
     
     
         22 . A prosthetic device for positioning between a first vertebra and a second vertebra, the device comprising:
 a first component comprising:
 a first bearing surface for engaging the first vertebra, the first bearing surface being substantially planar and having a first boundary, a second boundary opposite the first boundary, a third boundary extending between the first and second boundaries, and a fourth boundary opposite the third boundary and extending between the first and second boundaries; 
 a first elongated engagement member extending from and substantially perpendicular to the first bearing surface, the first elongated engagement member extending substantially parallel to at least portions of the third and fourth boundaries and along a majority of a length between the first and second boundaries, the first engagement member spaced from each of the first, second, third, and fourth boundaries and positioned closer to the third boundary than the fourth boundary; 
 a second elongated engagement member extending from and substantially perpendicular to the first bearing surface, the second elongated engagement member extending substantially parallel to the first elongated engagement member and extending along a majority of the length between the first and second boundaries, the second elongated engagement member spaced from the first engagement member and each of the first, second, third, and fourth boundaries, the second elongated engagement member positioned closer to the fourth boundary than the third boundary; and 
 a first articulation surface opposite the first bearing surface and defining a first articulation feature; 
   a second component comprising:
 a second engagement surface for engaging the second vertebra, the second engagement surface being substantially planar and having a first boundary, a second boundary opposite the first boundary, a third boundary extending between the first and second boundaries, and a fourth boundary opposite the third boundary and extending between the first and second boundaries; 
 a third elongated engagement member extending from and substantially perpendicular to the second engagement surface, the third elongated engagement member extending substantially parallel to at least portions of the third and fourth boundaries of the second engagement surface and along a majority of a length between the first and second boundaries of the second engagement surface, the third elongated engagement member spaced from each of the first, second, third, and fourth boundaries of the second engagement surface and positioned approximately equidistant to the third and fourth boundaries of the second engagement surface; and 
 a second articulation surface opposite the second engagement surface and defining a second articulation feature for articulating engagement with the first articulation feature of the first component. 
   
     
     
         23 . The device of  claim 22 , wherein the first articulation feature comprises a ball portion and the second articulation feature comprises a socket portion for articulating engagement with the ball portion. 
     
     
         24 . The device of  claim 22 , wherein the first, second, and third engagement members are substantially similar to one another. 
     
     
         25 . The device of  claim 24 , wherein the third engagement member extends substantially parallel to the first and second engagement members when the third and fourth boundaries of the first bearing surface are substantially parallel to the third and fourth boundaries of the second engagement surface. 
     
     
         26 . The device of  claim 24 , wherein the first, second, and third engagement members each comprise a flange member having a pair of substantially parallel, planar surfaces extending along a majority of the length of the flange member. 
     
     
         27 . The device of  claim 26 , wherein the width of the flange member is substantially constant along a majority of the length of the flange member. 
     
     
         28 . The device of  claim 27 , wherein the height of the flange member is tapered at least one end of the flange member. 
     
     
         29 . The device of  claim 28 , wherein the width of the flange member is tapered at the at least one end to define a sharp edge. 
     
     
         30 . The device of  claim 29 , wherein the first, second, and third engagement members each further comprise at least one opening extending through the flange member between the parallel, planar surfaces. 
     
     
         31 . The device of  claim 30 , wherein the first engagement member is spaced from the third boundary of the first bearing surface by a first distance and the second engagement member is spaced from the fourth boundary of the first bearing surface by a second distance, the first distance being substantially equal to the second distance. 
     
     
         32 . A spinal stabilization system for positioning between a first vertebra and a second vertebra, the device comprising:
 a first component comprising:
 a first bearing surface for engaging the first vertebra; 
 a first engagement structure extending from and substantially perpendicular to the first bearing surface, the first engagement structure extending along a majority of a length of the first bearing surface, the first engagement structure spaced from a center of the first bearing surface by a first distance; 
 a second engagement structure extending from and substantially perpendicular to the first bearing surface, the second engagement structure extending along a majority of a length of the first bearing surface and extending substantially parallel to the first engagement structure, the second engagement structure spaced from a center point of the first bearing surface by a second distance; and 
 a first articulation surface opposite the first bearing surface and defining a first articulation feature; 
   a second component comprising:
 a second engagement surface for engaging the second vertebra; 
 a third engagement structure extending from and substantially perpendicular to the second engagement surface, the second engagement structure extending along a majority of a length of the second engagement surface, the second engagement structure substantially centered on the second engagement surface; and 
 a second articulation surface opposite the second engagement surface and defining a second articulation feature, the second articulation feature in articulating engagement with the first articulation feature of the first component. 
   
     
     
         33 . The system of  claim 32 , wherein the first distance and the second distance are substantially equal. 
     
     
         34 . The system of  claim 33 , wherein the first engagement structure is spaced from a first edge of the first bearing surface extending at least partially parallel to the first engagement structure by a third distance, and wherein the first engagement structure is positioned between the first edge and the center of the first bearing surface. 
     
     
         35 . The system of  claim 34 , wherein the second engagement structure is spaced from a second edge of the first bearing surface extending at least partially parallel to the second engagement structure by a fourth distance, and wherein the second engagement structure is positioned between the second edge and the center point of the first bearing surface. 
     
     
         36 . The system of  claim 35 , wherein the third and fourth distances are substantially equal. 
     
     
         37 . The system of  claim 36 , wherein the first, second, and third engagement members are substantially similar to one another. 
     
     
         38 . The system of  claim 37 , wherein the first, second, and third engagement members each comprise a flange member having a pair of substantially parallel surfaces extending along a majority of the length of the flange member. 
     
     
         39 . The device of  claim 38 , wherein the height of the flange member is tapered at least one end of the flange member. 
     
     
         40 . The device of  claim 39 , wherein the width of the flange member is tapered at the at least one end to define a sharp edge. 
     
     
         41 . A prosthetic device for disposition within a space between a first vertebra and a second vertebra, the device comprising:
 a first component comprising:
 an anterior surface; 
 a posterior surface opposite the anterior surface and extending at least partially parallel to the anterior surface; 
 a first lateral surface extending between and generally perpendicular to the anterior and posterior surfaces; 
 a second lateral surface opposite the first lateral surface and extending between and generally perpendicular to the anterior and posterior surfaces; 
 an outer engagement surface bounded by the anterior, posterior, and first and second lateral surfaces; 
 a first elongated engagement member for penetrating and engaging the first vertebra extending from the outer engagement surface, the first engagement member extending substantially parallel to at least portions of the first and second lateral surfaces and being positioned closer to the first lateral surface than the second lateral surface, the first engagement member comprising a flange member having a pair of substantially parallel flange surfaces extending along a majority of the length of the flange member and a pair of througholes extending between the parallel surfaces, wherein a width of the flange member between the parallel flange surfaces is substantially constant along a majority of the flange member and tapers at least one end of the flange member to define a sharp edge; 
 a second elongated engagement member for penetrating and engaging the first vertebra extending from the outer engagement surface, the second engagement member extending substantially parallel to the first engagement member and being positioned closer to the second lateral surface than the first lateral surface, the second engagement member comprising a flange member having a pair of substantially parallel flange surfaces extending along a majority of the length of the flange member and a pair of througholes extending between the parallel surfaces, wherein a width of the flange member between the parallel flange surfaces is substantially constant along a majority of the flange member and tapers at least one end of the flange member to define a sharp edge; and 
 an inner articulation surface opposite the outer engagement surface and bounded by the anterior, posterior, and first and second lateral surfaces, the inner articulation surface defining a first articulation feature; and 
   a second component comprising:
 an anterior surface; 
 a posterior surface opposite the anterior surface and extending at least partially parallel to the anterior surface; 
 a first lateral surface extending between and generally perpendicular to the anterior and posterior surfaces; 
 a second lateral surface opposite the first lateral surface and extending between and generally perpendicular to the anterior and posterior surfaces; 
 an outer engagement surface bounded by the anterior, posterior, and first and second lateral surfaces; 
 a third elongated engagement member for penetrating and engaging the second vertebra extending from the outer engagement surface, the third engagement member extending substantially parallel to the first and second lateral surfaces and being centered on the outer engagement surface such that the third engagement member is substantially equidistance from the first and second lateral surfaces, the third engagement member comprising a flange member having a pair of substantially parallel flange surfaces extending along a majority of the length of the flange member and a pair of througholes extending between the parallel surfaces, wherein a width of the flange member between the parallel flange surfaces is substantially constant along a majority of the flange member and tapers at least one end of the flange member to define a sharp edge; and 
 an inner articulation surface opposite the outer engagement surface and bounded by the anterior, posterior, and first and second lateral surfaces, the inner articulation surface defining a second articulation feature for articulating engagement with the first articulation feature of the first component.