Method and device for restabilization with axial rotation of the atlantoaxial junction

Abstract

An apparatus for stabilizing an atlantoaxial junction while allowing for axial rotation in cases of acquired ligamentous injury or fracture of the dens.

1 . An apparatus to implant in a spine, comprising a means for stabilizing an atlantoaxial junction while allowing for axial rotation of stabilized vertebrae of the spine after implantation thereof, in cases of acquired ligamentous injury or fracture of the dens. 
     
     
         2 . An apparatus for implanting in a spine comprising:
 a first leg and second, physically distinct, leg, the first and second legs, respectively, having a first connection portion and a second connection portion, to connect the physically distinct first and second legs; and   a curved guide rod slidable within the first and second connection portions.   
     
     
         3 . The apparatus of  claim 2 , wherein the first leg comprises a first elongated shaft extending from the first connection portion along a first axis at an angle with respect to a vertical axis and the second, physically distinct, leg comprises a second elongated shaft extending from the second connection portion along a first axis at an angle with respect to the vertical axis. 
     
     
         4 . The apparatus of  claim 3 , wherein the first and second connection portions comprise first and second blocks that vertically extend, respectively, from the first and second elongated shafts along the vertical axis, wherein the blocks comprise respectively, first and second ovalized passages sized to allow passage of the curved guide. 
     
     
         5 . The apparatus of  claim 3 , wherein the first and second elongated shafts are adapted to be fastened, respectively, to a first and second polyaxial screw. 
     
     
         6 . The apparatus of  claim 5 , wherein the guide rod has a larger width than height to create an oval cross-section. 
     
     
         7 . The apparatus of  claim 2 , wherein the curved guide rod comprises a curve to mimic anatomic rotational motion of an average person. 
     
     
         8 . The apparatus of  claim 2 , wherein the first connection portion includes a through hole for free passage of a screw and wherein the second connection portion includes a threaded hole for threadably receiving the screw and a spacer therebetween. 
     
     
         9 - 14 . (canceled) 
     
     
         15 . The apparatus of  claim 2 , wherein the curved guide rod to limit translational motion and allow axial rotation of particular vertebrae. 
     
     
         16 . The apparatus of  claim 2 , wherein the curved guide rod comprises a guide for axial rotation of particular vertebrae. 
     
     
         17 . The apparatus of  claim 2 , comprising polyaxial screws to connect vertebrae respectively to the first and second connection portions. 
     
     
         18 . The apparatus of  claim 6 , comprising polyaxial screws to respectively attach the first block and the second block to vertebrae.