Spinal fixation system and method

Abstract

A spinal fixation system includes a first plate, a post fixedly attached to the first plate and extending transverse therefrom. A second plate receives the distal end of the post. A locking mechanism is configured to restrict at least one of axial translation and/or orbital rotation of the second plate with respect to the post. The locking mechanism can include a locking nut having two non-concentric cylinders which enable an interference fit between the nut and the post, thus restricting axial translation of the second plate.

1 - 20 . (canceled) 
     
     
         21 . A spinal fixation system, comprising:
 a first plate comprising a first end configured to engage a spinous process of a first vertebra and a second end configured to engage a spinous process of a second vertebra;   a post comprising a first end coupled to the first plate and a second end; and   a second plate comprising a first end configured to engage the spinous process of the first vertebra and a second end configured to engage the spinous process of the second vertebra, the second plate comprising an opening positioned between the first and second ends of the second plate, the opening having the second end of the post disposed therein such that the second plate is rotatable relative to the first plate.   
     
     
         22 . A system as recited in  claim 21 , wherein the first plate is axially fixed relative to the post such that the first plate is prevented from moving relative to the post along a longitudinal axis defined by the post. 
     
     
         23 . A system as recited in  claim 21 , wherein the post is rotatable relative to the first plate about a longitudinal axis defined by the post. 
     
     
         24 . A system as recited in  claim 21 , wherein the second plate is configured to translate axially relative to the first plate along a longitudinal axis defined by the post. 
     
     
         25 . A system as recited in  claim 21 , wherein the second plate is rotatable relative to the post in a plurality of planes. 
     
     
         26 . A system as recited in  claim 21 , wherein the first plate comprises an opening positioned between the first and second ends of the first plate, the first end of the post being disposed in the opening in the first plate. 
     
     
         27 . A system according to  claim 26 , wherein the post is retained within the opening in the first plate by a retaining ring. 
     
     
         28 . A system according to  claim 26 , wherein the opening in the first plate is coaxial with the opening in the second plate. 
     
     
         29 . A system according to  claim 21 , further comprising a nut positioned within the opening in the second plate, the nut comprising an aperture extending therethrough, the second end of the post being positioned within the aperture. 
     
     
         30 . A system according to  claim 29 , wherein the nut comprises a spherical outer surface that engages an arcuate inner surface of the second plate that defines the opening in the second plate such that the nut is rotatable relative to the second plate. 
     
     
         31 . A system according to  claim 29 , wherein the nut comprises a slit. 
     
     
         32 . A system according to  claim 29 , wherein the second end of the post extends completely through the aperture. 
     
     
         33 . A system according to  claim 29 , wherein the post is movable relative to the second plate between a first configuration in which a first length of the post extends outwardly from the nut and a second configuration in which an increased second length of the post extends outwardly from the nut. 
     
     
         34 . A system as recited in  claim 33 , wherein the first plate is spaced apart from the second plate by a first distance when the post is in the first configuration and is spaced apart from the second plate by a reduced second distance when the post is in the second configuration. 
     
     
         35 . A system as recited in  claim 21 , wherein an inner surface of the first plate faces an inner surface of the second plate, the inner surfaces each including a plurality of spikes extending outwardly therefrom. 
     
     
         36 . A system as recited in  claim 21 , wherein the second plate comprises an intermediate portion between the first and second ends of the second plate, the intermediate portion comprising the opening in the second plate, the second plate being free of any openings between the intermediate portion and the first end of the second plate and between the intermediate portion and the second end of the second plate. 
     
     
         37 . A system as recited in  claim 21 , wherein the first end of the post is removably coupled to the first plate. 
     
     
         38 . A system as recited in  claim 21 , wherein the first and second plates each have pre-defined bends along their lengths. 
     
     
         39 . A method for correction of a spinal disorder, comprising:
 providing the spinal fixation system recited in  claim 21 ;   engaging the first end of the first plate with a first side of the first vertebra and engaging the second end of the first plate with a first side of the second vertebra;   rotating the second plate relative to the post to position the second plate in a selected orientation; and   translating the second plate relative to the first plate along the post such that the second plate moves toward the first plate and the first end of the second plate engages a second side of the first vertebra and the second end of the second plate engages a second side of the second vertebra.   
     
     
         40 . A method as recited in  claim 39 , wherein:
 a nut is positioned within the opening in the second plate, the nut comprising an aperture extending therethrough, the second end of the post being positioned within the aperture; and   rotating the second plate comprises rotating the second plate about the nut while the nut is provisionally fixed relative to the post.