Artificial functional spinal unit assemblies

Abstract

An artificial functional spinal unit is provided comprising, generally, an expandable artificial intervertebral implant that can be placed via a posterior surgical approach and used in conjunction with one or more artificial facet joints to provide an anatomically correct range of motion. Expandable artificial intervertebral implants in both lordotic and non-lordotic designs are disclosed, as well as lordotic and non-lordotic expandable cages for both PLIF (posterior lumber interbody fusion) and TLIF (transforaminal lumbar interbody fusion) procedures. The expandable implants may have various shapes, such as round, square, rectangular, banana-shaped, kidney-shaped, or other similar shapes. By virtue of their posteriorly implanted approach, the disclosed artificial FSU's allow for posterior decompression of the neural elements, reconstruction of all or part of the natural functional spinal unit, restoration and maintenance of lordosis, maintenance of motion, and restoration and maintenance of disc space height.

1 - 53 . (canceled)  
     
     
         54 . An intervertebral implant for a human spine, comprising: 
 an upper body comprising an inferior surface and a superior surface, wherein the superior surface of the upper body is configured to engage a first vertebra of the human spine;    a lower body comprising a superior surface and an inferior surface, wherein the inferior surface of the lower body is configured to engage a second vertebra of the human spine;    an insert configured to be positioned in a channel of the lower body and between the superior surface of the lower body and the inferior surface of the upper body before insertion of the intervertebral implant between the first vertebra and the second vertebra of the human spine;    an expansion member configured to engage the insert to increase a separation distance between the upper body and the lower body after insertion of the intervertebral implant in the human spine; and    wherein the intervertebral implant is configured such that increasing the separation distance between the upper body and the lower body allows increased articulation of the intervertebral implant.    
     
     
         55 . The intervertebral implant of  claim 54 , wherein the inferior surface of the upper body is at least partially concave.  
     
     
         56 . The intervertebral implant of  claim 54 , wherein the inferior surface of the upper body is at least partially concave, and such inferior surface comprises one or more edges that, as the separation distance between the upper body and the lower body increases, can move more relative to the lower body, thereby allowing increased articulation of the intervertebral implant.  
     
     
         57 . The intervertebral implant of  claim 54 , wherein the inferior surface of the upper body is at least partially concave, and such inferior surface comprises at least one substantially flat surface that, prior to engagement of the expansion member, is configured to contact another surface of the intervertebral implant and thus inhibit articulation.  
     
     
         58 . The intervertebral implant of  claim 54 , wherein the inferior surface of the upper body is at least partially concave, and such inferior surface comprises at least one substantially flat surface that, prior to engagement of the expansion member, is configured to contact another surface of the intervertebral implant and thus inhibit articulation, and after the separation distance between the upper body and the lower body is increased, the upper body is allowed to articulate with respect to the lower body such that the substantially flat surface of the upper body is at an angle of between 0-180° to another substantially flat surface of the intervertebral implant.  
     
     
         59 . The intervertebral implant of  claim 54 , wherein the expansion member comprises an expansion plate.  
     
     
         60 . The intervertebral implant of  claim 54 , wherein the implant is configured such that increasing the separation distance between the upper body and the lower body increases a height of the intervertebral implant.  
     
     
         61 . An intervertebral implant for a human spine, comprising: 
 an upper body comprising an inferior surface and a superior surface, wherein the superior surface of the upper body is configured to engage a first vertebra of the human spine;    a lower body comprising a superior surface and an inferior surface, wherein the inferior surface of the lower body is configured to engage a second vertebra of the human spine;    an insert comprising a superior surface and an inferior surface, wherein the insert is configured to be positioned in a channel of the lower body and between the superior surface of the lower body and the inferior surface of the upper body before insertion of the intervertebral implant between the first vertebra and the second vertebra of the human spine;    an expansion member configured to engage the insert to increase a separation distance between the upper body and the lower body after insertion of the intervertebral implant in the human spine, wherein the intervertebral implant is configured such that increasing the separation distance between the upper body and the lower body allows increased articulation of the intervertebral implant; and    wherein the intervertebral implant comprises a substantially elongated anterior side, a substantially elongated posterior side, and two ends, and wherein the intervertebral implant comprises an opening on or proximate the posterior side or on or proximate one of the ends for insertion or engagement of the expansion member from a posterior approach after insertion of the intervertebral implant in the human spine.    
     
     
         62 . The intervertebral implant of  claim 61 , wherein the upper body and the lower body are substantially banana-shaped.  
     
     
         63 . The intervertebral implant of  claim 61 , wherein the inferior surface of the insert is substantially flat.  
     
     
         64 . The intervertebral implant of  claim 61 , wherein the inferior surface of the insert is substantially flat, wherein at least a portion of the superior surface of the lower body is substantially flat, and wherein the substantially flat inferior surface of the insert is configured to rest on the substantially flat portion of the superior surface of the lower body before the separation distance between the upper body and the lower body is increased.  
     
     
         65 . An intervertebral implant for a human spine, comprising: 
 an upper body comprising an inferior surface and a superior surface, wherein the superior surface of the upper body is configured to engage a first vertebra of the human spine;    a lower body comprising a superior surface and an inferior surface, wherein the inferior surface of the lower body is configured to engage a second vertebra of the human spine;    an insert configured to be positioned between the superior surface of the lower body and the inferior surface of the upper body such that a height of the intervertebral implant is substantially equal to a height of the lower body plus a height of the upper body before insertion of the intervertebral implant in the human spine; and    an expansion member configured to engage and raise the insert above the superior surface of the lower body to increase a separation distance between the upper body and the lower body after insertion of the intervertebral implant in the human spine.    
     
     
         66 . The intervertebral implant of  claim 65 , wherein the superior surface of the lower body comprises a substantially flat edge, and wherein the inferior surface of the upper body comprises a concave portion at least partially surrounded by a substantially flat edge.  
     
     
         67 . The intervertebral implant of  claim 65 , wherein the superior surface of the lower body comprises a substantially flat edge, wherein the inferior surface of the upper body comprises a concave portion at least partially surrounded by a flat edge, and wherein at least a portion of the substantially flat edge of the upper body rests on at least a portion of the substantially flat edge of the lower body with the insert positioned between the superior surface of the lower body and the inferior surface of the upper body before engagement of the expansion member.  
     
     
         68 . The intervertebral implant of  claim 65 , wherein increasing the separation distance between the upper body and the lower body allows articulation of the intervertebral implant.  
     
     
         69 . An intervertebral implant for a human spine, comprising: 
 an upper body comprising an inferior surface and a superior surface, wherein the superior surface of the upper body is configured to engage a first vertebra of the human spine;    a lower body comprising a superior surface and an inferior surface, wherein the inferior surface of the lower body is configured to engage a second vertebra of the human spine;    an insert comprising a superior surface and an inferior surface, wherein the insert is configured to be positioned between the superior surface of the lower body and the inferior surface of the upper body such that a height of the intervertebral implant exceeds a height of the lower body plus a height of the upper body;    an expansion member configured to engage and raise the insert above the superior surface of the lower body to increase a separation distance between the upper body and the lower body after insertion of the intervertebral implant in the human spine; and    wherein the implant is configured such that increasing the separation distance between the upper body and the lower body allows increased articulation of the intervertebral implant.    
     
     
         70 . The intervertebral implant of  claim 69 , wherein the superior surface of the lower body comprises at least one substantially flat portion, wherein the inferior surface of the insert is substantially flat, and wherein the substantially flat inferior surface of the insert is configured to rest on at least one of the substantially flat portions of the superior surface of the lower body before engagement of the expansion member.  
     
     
         71 . The intervertebral implant of  claim 69 , wherein increasing the separation distance between the upper body and the lower body increases a height of the intervertebral implant.  
     
     
         72 . The intervertebral implant of  claim 69 , wherein at least a portion of the superior surface of the insert is convex, wherein at least a portion of the inferior surface of the upper body is concave, wherein the concave portion of the inferior surface of the upper body is configured to rest on the convex portion of the insert, and wherein increasing the separation distance between the upper body and the lower body allows an increased range of angular motion of the upper body relative to the insert.  
     
     
         73 - 92 . (canceled)  
     
     
         93 . An intervertebral implant for a human spine, comprising: 
 an upper body comprising an inferior surface and a superior surface, wherein the superior surface of the upper body is configured to engage a first vertebra of the human spine;    a lower body comprising a superior surface and an inferior surface, wherein the inferior surface of the lower body is configured to engage a second vertebra of the human spine;    an insert comprising a superior surface and an inferior surface, wherein the insert is configured to be positioned between the superior surface of the lower body and the inferior surface of the upper body before insertion of the intervertebral implant between the first vertebra and the second vertebra of the human spine;    an expansion member configured to engage the insert to increase a separation distance between the upper body and the lower body to allow increased articulation of the intervertebral implant after insertion of the intervertebral implant in the human spine; and    wherein increasing the separation distance between the upper body and the lower body comprises elevating the insert from the lower body by a distance substantially equivalent to a height of the expansion member.    
     
     
         94 . The intervertebral implant of  claim 93 , wherein the expansion member comprises an expansion plate, and wherein the height of the expansion member is the thickness of the expansion plate.  
     
     
         95 . The intervertebral implant of  claim 93 , wherein the expansion member comprises an expansion plate, and wherein the expansion plate is configured to be inserted between the superior surface of the lower body and the inferior surface of the insert to increase the separation distance between the upper body and the lower body.  
     
     
         96 . The intervertebral implant of  claim 93 , wherein at least a portion of the inferior surface of the upper body is concave, wherein at least a portion of the superior surface of the insert is convex, wherein the concave portion of the inferior surface of the upper body rests on the convex portion of the superior surface of the insert, and wherein increasing the separation distance between the upper body and the lower body allows movement or increased movement of the concave portion of the inferior surface of the upper body about the convex portion of the superior surface of the insert.  
     
     
         97 - 106 . (canceled)