Prostheses, Systems and Methods for Replacement of Natural Facet Joints With Artificial Facet Joint Surfaces

Abstract

Cephalad and caudal vertebral facet joint prostheses and methods of use are provided. A pair of fixation elements are adapted to be secured within a vertebra in an orientation that best assures a secure and durable attachment to cortical and/or cancellous bone. Artificial facet joint surfaces are mounted on the fixation elements, either directly or with the aid of a support. The artificial facet joint structure may be carried by an arm. The artificial facet joint structure is adapted for articulation with a complementary natural or artificial facet joint structure. Bilateral prostheses may by coupled by a brace to further secure and stabilize the prostheses.

1 . A spinal stabilization device, comprising: a central spacer with at least two arms extending therefrom and adapted to couple to adjacent vertebrae, the central spacer and the at least two arms having a unitary configuration and being formed from an elastomeric material.  
     
     
         2 . The spinal stabilization device of  claim 1 , wherein the at least two arms comprises first and second superior arms extending from a superior portion of the central spacer and adapted to mate to a superior vertebra, and first and second inferior arms extending from an inferior portion of the central spacer and adapted to mate to an inferior vertebra.  
     
     
         3 . A spinal stabilization device, comprising: a central spacer adapted to be positioned between posterior elements of adjacent vertebrae and adapted to limit extension of the adjacent vertebrae, and at least one pair of arms extending from opposed sides of the central spacer and adapted to couple to a vertebra, at least a portion of the at least one pair of arms being pliable for providing resistance to movement of adjacent vertebrae coupled thereto.  
     
     
         4 . The spinal stabilization device of  claim 3 , wherein the at least one pair of arms and the central spacer are of a unitary construction.  
     
     
         5 . The spinal stabilization device of  claim 4 , wherein the at least one pair of arms and the central spacer are formed from an elastomeric material.  
     
     
         6 . The spinal stabilization device of  claim 3 , wherein the at least one pair of arms is removably coupled to the central spacer.  
     
     
         7 . The spinal stabilization device of  claim 3 , wherein at least one of the at least one pair of arms is slidably disposed through the central spacer.  
     
     
         8 . The spinal stabilization device of  claim 3 , wherein the central spacer has a shape selected from the group consisting of wedge-shaped, round, oval, elliptical, and rectangular.  
     
     
         9 . The spinal stabilization device of  claim 3 , wherein the at least one pair of arms comprises first and second arms extending from opposed sides of the central spacer, a third arm removably coupled to the first arm, and a fourth arm removably coupled to the second arm.  
     
     
         10 . The spinal stabilization device of  claim 3 , wherein the central spacer is formed from a compressible material.  
     
     
         11 . The spinal stabilization device of  claim 3 , wherein the at least one pair of arms is adjustably matable to the central spacer.  
     
     
         12 . The spinal stabilization device of  claim 3 , wherein the central spacer is adapted to at least partially rotate relative to the at least one pair of arms.  
     
     
         13 . The spinal stabilization device of  claim 3 , wherein the at least one pair of arms comprises a first pair of arms extending from a first lateral side of the central spacer, and a second pair arms extending from a second, opposed lateral side of the central spacer.  
     
     
         14 . The spinal stabilization device of  claim 13 , wherein the first pair of arms are integrally formed with one another, and the second pair of arms are integrally formed with one another.  
     
     
         15 . The spinal stabilization device of  claim 14 , wherein the first and second pair of arms are adapted to mate to the central spacer at a variety of angular orientations.  
     
     
         16 . The spinal stabilization device of  claim 14 , wherein the central spacer includes a cross-connector extending therethrough and adapted to engage the first and second pair of arms.  
     
     
         17 . The spinal stabilization device of  claim 16 , wherein the cross-connector is slidably adjustable relative to the first and second pair of arms to allow the central spacer to be mated to the first and second pair of arms at a plurality of positions.  
     
     
         18 . The spinal stabilization device of  claim 3 , wherein the device is substantially X-shaped.  
     
     
         19 . A spinal stabilization device, comprising: a central spacer having first and second opposed lateral sides, the central spacer being adapted to be positioned between posterior elements of adjacent superior and inferior vertebrae and adapted to limit extension of the adjacent superior and inferior vertebrae; a first pair of arms extending from the first lateral side of the central spacer, the first pair of arms being adapted to couple to adjacent superior and inferior vertebrae; and a second pair of arms extending from the second lateral side of the central spacer, the second pair of arms being adapted to couple to adjacent superior and inferior vertebrae; wherein at least a portion of at least one of the first and second pair of arms is pliable for providing resistance to movement of adjacent superior and inferior vertebrae coupled thereto.  
     
     
         20 . The spinal stabilization device of  claim 19 , wherein the first pair of arms are coupled to one another and the second pair of arms are coupled to one another, and wherein the first and second pair of arms are removably mated to the central spacer.  
     
     
         21 . The spinal stabilization device of  claim 19 , wherein the first pair of arms comprises a first arm and a second arm, and the second pair of arms comprises a third arm and a fourth arm, and wherein the first, second, third, and fourth arms are independently removably mated to the central spacer.  
     
     
         22 . The spinal stabilization device of  claim 21 , wherein the central spacer includes a first opening formed in the first lateral side and adapted to removably receive the first and second arms, and a second opening formed in the second, opposed lateral side and adapted to removably receive the third and fourth arms.  
     
     
         23 . The spinal stabilization device of  claim 22 , wherein the central spacer includes first and second locking mechanisms adapted to be disposed through the first and second openings for locking the first, second, third, and fourth arms to the central spacer.