Spinal Fusion Implants And Methods For Deploying Such Implants

Abstract

Methods and apparatus are disclosed for distracting tissue. The devices and methods may include insertion of first and second elongated members into the space between two tissue layers, with an augmenting elongated member inserted therebetween to form a distraction device between the tissues to be distracted. The distraction device defines a generally annular configuration, with a locking member secured to one of the elongated members at a plurality of locations to maintain the distraction device in the generally annular configuration. The augmenting elongated member may be shorter than the first and second elongated members such that a window is defined between the proximal and distal ends of the augmenting elongated member when the distraction device and the first and second elongated members are in the generally annular configuration. Bone graft material or bone filler may be introduced into the interior of the distraction device through the window.

1 - 27 . (canceled) 
     
     
         28 . A tissue distraction device comprising a plurality of elongated members insertable between adjacent tissue layers of a spine, wherein
 one of the plurality of elongated members is configured to engage an upper tissue layer,   another one of the plurality of elongated members is configured to engage a lower tissue layer, and   an elongated element is associated with at least one of the plurality of elongated members, at least partially formed of a material having shape memory properties, and configured to automatically move said at least one of the plurality of elongated members from a constrained, generally linear configuration to an unconstrained, generally less linear configuration.   
     
     
         29 . The tissue distraction device of  claim 28 , wherein said material comprises Nitinol. 
     
     
         30 . The tissue distraction device of  claim 28 , wherein said material comprises a shape memory polymer. 
     
     
         31 . The tissue distraction device of  claim 28 , wherein the elongated element is at least partially positioned within said at least one of the plurality of elongated members. 
     
     
         32 . The tissue distraction device of  claim 28 , wherein the elongated element is fully embedded within said at least one of the plurality of elongated members. 
     
     
         33 . The tissue distraction device of  claim 28 , wherein the elongated element is secured to an outer surface of said at least one of the plurality of elongated members. 
     
     
         34 . The tissue distraction device of  claim 33 , wherein the elongated element is secured to a lateral side of said at least one of the plurality of elongated members. 
     
     
         35 . The tissue distraction device of  claim 28 , wherein the elongated element is configured as a wire. 
     
     
         36 . The tissue distraction device of  claim 28 , wherein the elongated element is configured as a tube. 
     
     
         37 . The tissue distraction device of  claim 28 , wherein said at least one of the plurality of elongated members comprises an augmenting elongated member configured to be at least partially positioned between said one of the plurality of elongated members and said another one of the plurality of elongated members. 
     
     
         38 . The tissue distraction device of  claim 28 , wherein the elongated element is associated with said one of the plurality of elongated members or said another one of the plurality of elongated members. 
     
     
         39 . The tissue distraction of  claim 28 , further comprising a second elongated element, wherein the elongated elements are associated with different elongated members. 
     
     
         40 . The tissue distraction device of  claim 28 , wherein said unconstrained, generally less linear configuration comprises an arcuate configuration. 
     
     
         41 . The tissue distraction device of  claim 28 , wherein said unconstrained, generally less linear configuration comprises an annular configuration. 
     
     
         42 . A method of assembling a structure in vivo between two body tissue layers comprising first and second elongated members and an augmenting elongated member, the method comprising:
 delivering the first and second elongated members between two body tissue layers in a generally linear configuration to define at least a portion of a structure having a dimensional aspect in a direction extending generally from one of said body tissue layers to the other body tissue layer; and   inserting at least a portion of the augmenting elongated member between and in contact with said first and second elongated members to spread the first and second elongated members apart to increase the dimensional aspect of at least a portion of the structure, wherein
 an elongated element at least partially formed of a material having shape memory properties is associated with the augmenting elongated member, and 
 said inserting said at least a portion of the augmenting elongated member between and in contact with said first and second elongated members includes the elongated element causing said at least a portion of the augmenting elongated member to automatically move from a constrained, generally linear configuration to an unconstrained, generally less linear configuration. 
   
     
     
         43 . The method of  claim 42 , wherein said material comprises Nitinol. 
     
     
         44 . The method of  claim 42 , wherein the elongated element is fully embedded within the augmenting elongated member. 
     
     
         45 . The method of  claim 42 , wherein the elongated element is configured as a wire. 
     
     
         46 . The method of  claim 42 , wherein said unconstrained, generally less linear configuration comprises an arcuate configuration. 
     
     
         47 . The method of  claim 42 , wherein said unconstrained, generally less linear configuration comprises an annular configuration.