Hybrid multifunctional posterior interspinous fusion device

Abstract

An interspinous stabilization device is provided that more evenly distributes loads throughout the adjacent vertebrae than known interspinous stabilization devices, and further can readily compensate for graft settling so as to maintain continued axial loading of the graft material.

What is claimed is: 
     
         1 . An interspinous stabilization device comprising:
 a body portion;   a pair of mounting plates supported on the body portion and adapted to engage a first vertebra; and   a pair of connecting plates supported on the body portion and adapted to engage a second vertebra,   wherein the interspinous stabilization device is adapted to maintain continued axial loading of a graft disposed between the first and second vertebra as settling of the graft occurs.   
     
     
         2 . The interspinous stabilization device defined in  claim 1 , wherein one or both of the mounting plates are shaped having a torsional twist. 
     
     
         3 . The interspinous stabilization device defined in  claim 1 , wherein one or both of the mounting plates has an aperture formed therethrough that is shaped to permit a fastener to extend therethrough at multiple locations. 
     
     
         4 . The interspinous stabilization device defined in  claim 1 , wherein one or both of the connecting plates has a slot-shaped aperture formed therethrough. 
     
     
         5 . The interspinous stabilization device defined in  claim 1 , wherein the body portion is defined by a bottom wall, first and second opposed side walls, and a rear wall that cooperate to define a partially enclosed space for the receipt of a bone graft material. 
     
     
         6 . The interspinous stabilization device defined in  claim 1 , wherein one or both of the mounting plates is fixed in position relative to the body portion. 
     
     
         7 . The interspinous stabilization device defined in  claim 1 , wherein one or both of the mounting plates is movable relative to the body portion and lockable in a desired position relative thereto. 
     
     
         8 . The interspinous stabilization device defined in  claim 1 , wherein the body portion is defined by a bottom wall, first and second opposed side walls, and a rear wall, and wherein a hinge is provided between the bottom wall and the rear wall to allow relative pivoting movement therebetween. 
     
     
         9 . The interspinous stabilization device defined in  claim 8 , further including a movement-limiting mechanism to restrict the pivoting movement of the rear wall relative to the bottom wall to a single rotational direction. 
     
     
         10 . The interspinous stabilization device defined in  claim 1 , wherein one or both of the mounting plates has a generally uniform thickness. 
     
     
         11 . The interspinous stabilization device defined in  claim 1 , wherein one or both of the mounting plates varies in thickness from end to end. 
     
     
         12 . The interspinous stabilization device defined in  claim 1 , wherein one or both of the mounting plates is linear from end to end. 
     
     
         13 . The interspinous stabilization device defined in  claim 1 , wherein one or both of the mounting plates is curved from end to end. 
     
     
         14 . The interspinous stabilization device defined in  claim 1 , wherein one or both of the mounting plates has a slot-shaped aperture formed therethrough. 
     
     
         15 . The interspinous stabilization device defined in  claim 5 , wherein one or both of the side walls are pivotably connected to the rear wall. 
     
     
         16 . The interspinous stabilization device defined in  claim 5  wherein one or both of the mounting plates are pivotably connected to the rear wall. 
     
     
         17 . The interspinous stabilization device defined in  claim 1 , wherein either or both of the pair of mounting plates is pivotably supported on the body portion. 
     
     
         18 . The interspinous stabilization device defined in  claim 1 , wherein either or both of the pair of connecting plates is pivotably supported on the body portion. 
     
     
         19 . The interspinous stabilization device defined in  claim 1 , wherein the body portion includes a spring-like hinge between the pair of mounting plates and the pair of connecting plates. 
     
     
         20 . The interspinous stabilization device defined in  claim 19 , wherein the spring-like hinge is defined by a slot that extends between the pair of mounting plates and the pair of connecting plates. 
     
     
         21 . The interspinous stabilization device defined in  claim 19 , wherein the slot has a length of about 12 mm. 
     
     
         22 . The interspinous stabilization device defined in  claim 19 , wherein the slot expands at an angular relationship of about 2°. 
     
     
         23 . The interspinous stabilization device defined in  claim 1 , wherein the body portion includes a hinge between the pair of mounting plates and the pair of connecting plates. 
     
     
         24 . The interspinous stabilization device defined in  claim 23 , wherein the hinge includes a pivot pin that extends through portions of the pair of mounting plates and the pair of connecting plates. 
     
     
         25 . The interspinous stabilization device defined in  claim 24 , further including a mechanism for maintaining the pair of mounting plates in a predetermined position relative to the pair of connecting plates. 
     
     
         26 . The interspinous stabilization device defined in  claim 25 , wherein the mechanism for maintaining includes a locking nut provided on the pivot pin. 
     
     
         27 . The interspinous stabilization device defined in  claim 1 , wherein the interspinous fusion device is split into two separate lateral portions that are supported on one another. 
     
     
         28 . The interspinous stabilization device defined in  claim 27 , wherein a first lateral portion has a protrusion provided thereon, and wherein a second lateral portion has a recess provided therein that receives the protrusion. 
     
     
         29 . The interspinous stabilization device defined in  claim 28 , wherein the recess and the protrusion are sized and shaped in a complementary manner. 
     
     
         30 . The interspinous stabilization device defined in  claim 28 , wherein the recess and the protrusion are U-shaped. 
     
     
         31 . An interspinous stabilization device that is connected to a plate so as to directly stabilize a spinous process with a facet joint in a vertebra in a spine.