Posterior stabilization systems and methods

Abstract

Various methods and devices for repairing and/or restoring function to a damaged, injured, diseased, or otherwise unhealthy facet joint, lamina, posterior ligament, and/or other features of a patient's spinal column are provided. In an exemplary embodiment, the methods and devices are effective to mimic the natural function of the posterior elements, preferably without necessarily mimicking the anatomy, by allowing a high degree of flexibility between two adjacent vertebrae when the vertebrae are moved within a first range of motion, and by controlling movement of the adjacent vertebrae within a second range of motion beyond the first range of motion.

1 . An implantable device for stabilizing the spine, comprising: 
 at least one flexible member adapted to span across at least two adjacent vertebrae in a patient's spinal column;    a superior connector adapted to be coupled to a superior vertebra and an inferior connector adapted to be coupled to an inferior vertebra, the superior and inferior connectors extending through the at least one flexible member such that the superior and inferior connectors and the at least one flexible member are effective to control movement between the superior and inferior vertebrae.    
   
   
       2 . The implantable device of  claim 1 , wherein the superior connector is movable relative to the at least one flexible member.  
   
   
       3 . The implantable device of  claim 1 , further comprising first and second flexible members.  
   
   
       4 . The implantable device of  claim 1 , wherein each flexible member includes at least two thru-bores formed therein for receiving the superior and inferior connectors therethrough.  
   
   
       5 . The implantable device of  claim 4 , wherein each thru-bore includes a bushing disposed therein and adapted to receive a connector therethrough.  
   
   
       6 . The implantable device of  claim 4 , wherein each thru-bore includes a bearing formed therein and adapted to receive a connector therethrough.  
   
   
       7 . The implantable device of  claim 4 , wherein a region surrounding each thru-bore is adapted to provide stability to the connector extending therethrough.  
   
   
       8 . The implantable device of  claim 7 , wherein each region is substantially rigid.  
   
   
       9 . The implantable device of  claim 1 , wherein each connector comprises a substantially rigid rod.  
   
   
       10 . The implantable device of  claim 1 , wherein the superior connector includes opposed terminal ends that are adapted to be coupled to pedicles of a superior vertebra, and a mid-portion that is adapted to extend around and be positioned inferior to a spinous process of a superior vertebra, and wherein the inferior connector includes opposed terminal ends that are adapted to be coupled to pedicles of an inferior vertebra, and a mid-portion that is adapted to be positioned proximate and superior to a spinous process of an inferior vertebra.  
   
   
       11 . The implantable device of  claim 10 , wherein the superior connector is substantially v-shaped and the inferior connector is generally linear with a v-shaped portion formed therein.  
   
   
       12 . The implantable device of  claim 11 , wherein the v-shaped portion in the inferior connector is formed at a substantial mid-point thereof.  
   
   
       13 . The implantable device of  claim 12 , wherein the v-shaped portion in the inferior connector is adapted to fit around a spinous process of an inferior vertebra.  
   
   
       14 . The implantable device of  claim 11 , wherein the v-shaped superior connector includes a central linear portion and first and second lateral arms extending at an angle relative to the central linear portion.  
   
   
       15 . The implantable device of  claim 1 , wherein each connector includes first and second terminal ends adapted to be fixedly mated to opposed sides of a vertebra.  
   
   
       16 . The implantable device of  claim 15 , further comprising a plurality of spinal anchors, each being adapted to be implanted in a vertebra and to fixedly mate a terminal end of a connector to the vertebra.  
   
   
       17 . The implantable device of  claim 16 , wherein each spinal anchor comprises a spinal screw having a rod-receiving head formed thereon, and wherein each connector comprises a rod.  
   
   
       18 . The implantable device of  claim 1 , wherein the at least one flexible member is formed from a material selected from the group consisting of polyurethane, composite reinforced polyurethane, and silicones.  
   
   
       19 . The implantable device of  claim 1 , wherein the at least one flexible member comprises a single flexible member having a substantially hour-glass shape.  
   
   
       20 . The implantable device of  claim 1 , wherein the at least one flexible member has a central portion that has an elasticity that is greater than an elasticity of opposed superior and inferior terminal ends thereof.  
   
   
       21 . An implantable device for stabilizing the spine, comprising: 
 first and second dynamic stabilizing members adapted to be positioned adjacent to opposed sides of a spinous process and to extend along at least two adjacent vertebrae in a patient's spinal column; and    at least one pair of stabilizing rods adapted to extend through the first and second dynamic stabilizing members and to couple to two adjacent vertebrae to control movement between the adjacent vertebrae.    
   
   
       22 . The implantable device of  claim 21 , wherein the first and second dynamic stabilizing members are substantially flexible.  
   
   
       23 . The implantable device of  claim 22 , wherein the first and second dynamic stabilizing members each have a flexibility that varies along a length thereof.  
   
   
       24 . The implantable device of  claim 22 , wherein the first and second dynamic stabilizing members each have a mid-portion having a flexibility that is greater than a flexibility of opposed terminal ends thereof.  
   
   
       25 . The implantable device of  claim 21 , wherein a pair of stabilizing rods comprises a superior stabilizing rod and an inferior stabilizing rod, and wherein the first and second dynamic stabilizing members each include a superior hole formed therein and adapted to receive the superior stabilizing rod, and an inferior hole formed therein and adapted to receive the inferior stabilizing rod.  
   
   
       26 . The implantable device of  claim 25 , wherein the superior stabilizing member includes opposed terminal ends that are adapted to be coupled to pedicles of a vertebra, and a mid-portion that is adapted to extend around and be positioned inferior to a spinous process of a vertebra.  
   
   
       27 . The implantable device of  claim 25 , wherein the inferior stabilizing member includes opposed terminal ends that are adapted to be coupled to pedicles of an inferior vertebra, and a mid-portion that is adapted to be positioned proximate and inferior to a spinous process of an adjacent superior vertebra.  
   
   
       28 . The implantable device of  claim 25 , wherein the superior stabilizing member has a generally elongate shape with a v-shaped portion formed therein, and wherein the inferior stabilizing member is substantially v-shaped.  
   
   
       29 . The implantable device of  claim 25 , wherein the superior and inferior holes in the first and second dynamic stabilizing members each include a bearing element disposed therein and adapted to receive the stabilizing rod.  
   
   
       30 . The implantable device of  claim 25 , wherein the superior and inferior holes in the first and second dynamic stabilizing members are adapted to rigidly support the stabilizing rod relative to the dynamic stabilizing member.  
   
   
       31 . The implantable device of  claim 30 , wherein a region surrounding the superior and inferior holes in the first and second dynamic stabilizing members have an elasticity that is less than an elasticity of the remainder of the first and second dynamic stabilizing members.  
   
   
       32 . A posterior element replacement implant, comprising: 
 at least one flexible member; and    at least one connector adapted to be coupled to adjacent vertebrae and adapted to extend through the at least one flexible member;    wherein the at least one connector is adapted to move relative to the at least one flexible member without substantially deforming the at least one flexible member when the adjacent vertebrae are moved within a first range of motion, and wherein the at least one connector is adapted to deform the at least one flexible member when the adjacent vertebrae are moved within a second range of motion beyond the first range of motion.    
   
   
       33 . The implant of  claim 32 , wherein the at least one connector comprises a superior connector and an inferior connector.  
   
   
       34 . The implant of  claim 33 , wherein the superior and inferior connectors each comprise a substantially rigid rod.  
   
   
       35 . The implant of  claim 34 , wherein the superior rod is substantially v-shaped, and the inferior rod is substantially linear with a v-shaped portion formed therein.  
   
   
       36 . The implant of  claim 33 , wherein the at least one flexible member comprises first and second flexible members.  
   
   
       37 . The implant of  claim 36 , wherein the first and second flexible members each have a substantially elongate shape with first and second thru-bores formed therein for receiving the superior and inferior connectors.  
   
   
       38 . The implant of  claim 37 , wherein each thru-bore includes a bearing formed therein and adapted to receive a connector extending therethrough.  
   
   
       39 . An implantable posterior element repair kit, comprising: 
 a plurality of pairs of dynamic stabilizing members, each pair comprising first and second dynamic stabilizing members adapted to be positioned adjacent to opposed sides of a spinous process and to extend along at least two adjacent vertebrae in a patient's spinal column; and    a plurality of pairs of stabilizing rods, each pair of stabilizing rods being adapted to couple to a pair of dynamic stabilizing members and to couple to two adjacent vertebrae to control movement between the adjacent vertebrae.    
   
   
       40 . The kit of  claim 39 , wherein each of the plurality of pairs of dynamic stabilizing members has an elasticity that differs from one another.  
   
   
       41 . The kit of  claim 39 , wherein each of the plurality of pairs of dynamic stabilizing members has a size that differs from one another.  
   
   
       42 . The kit of  claim 39 , wherein each of the plurality of pairs of dynamic stabilizing members has a shape that differs from one another.  
   
   
       43 . A method for stabilizing the posterior element in adjacent vertebrae, comprising: 
 coupling at least one flexible member to two adjacent vertebrae with at least one connector such that the at least one connector is movable relative to the at least one flexible member without substantially deforming the at least one flexible member when the vertebrae are moved within a first range of motion, and such that the at least one connector is effective to deform the at least one flexible member when the vertebrae are moved within a second range of motion beyond the first range of motion.    
   
   
       44 . The method of  claim 43 , wherein the step of coupling at least flexible member to two adjacent vertebrae with at least one connector comprises coupling a superior connector to a superior vertebra, the superior connector extending through first and second flexible members, and coupling an inferior connector to an inferior vertebra, the inferior connector extending through the first and second flexible members.  
   
   
       45 . The method of  claim 44 , wherein the step of coupling the superior connector to the superior vertebra comprises implanting first and second spinal anchors in the superior vertebra and locking the superior connector to the first and second spinal anchors, and wherein the step of coupling the inferior connector to the inferior vertebra comprises implanting first and second spinal anchors in the inferior vertebra and locking the inferior connector to the first and second spinal anchors.  
   
   
       46 . A method for mimicking the normal function of adjacent vertebrae in a patient's spinal column, comprising: 
 implanting a first pair of spinal anchors in opposed pedicles of a first vertebra, and implanting a second pair of spinal anchors in opposed pedicles of an adjacent second vertebra;    coupling opposed terminal ends of a first rigid member to the first pair of spinal anchors in the first vertebra, and coupling opposed terminal ends of a second rigid member to the second pair of spinal anchors in the second vertebra, the first and second rigid members extending through at least one flexible member.    
   
   
       47 . The method of  claim 46 , wherein the at least one flexible member comprises first and second flexible members positioned on opposed sides of a spinous process of each vertebra.  
   
   
       48 . The method of  claim 46 , wherein the first rigid member is substantially v-shaped, and the second rigid member is substantially linear with a v-shaped portion formed therein.  
   
   
       49 . The method of  claim 46 , wherein the first rigid member extends from the opposed pedicles inferior to a spinous process of the first vertebra, and wherein the second rigid member extends from the opposed pedicles superior to a spinous process of the second vertebra.  
   
   
       50 . The method of  claim 46 , wherein each spinal anchor comprises a spinal screw having a receiver head formed thereon and adapted to seat a terminal end of a rigid member.  
   
   
       51 . The method of  claim 46 , further comprising the steps of implanting a third pair of spinal anchors in opposed pedicles of a third vertebra adjacent to the second vertebra, coupling opposed terminal ends of a third rigid member to the second pair of spinal anchors in the second vertebra, and coupling opposed terminal ends of a fourth rigid member to the third pair of spinal anchors in the third vertebra, the third and fourth rigid members extending through the at least one flexible member.  
   
   
       52 . A method for providing stability to adjacent vertebrae, comprising coupling a superior stabilizing rod to opposed sides of a superior vertebra and coupling an inferior stabilizing rod to opposed sides of an inferior vertebra such that movement between the superior and inferior vertebrae is controlled by at least one flexible member coupled to each of the superior and inferior stabilizing rods.  
   
   
       53 . The method of  claim 52 , wherein the superior stabilizing rod is adapted to move relative to the at least one flexible member without substantially deforming the at least one flexible when the superior and inferior vertebrae are moved relative to one another within a first range of motion, and wherein the superior stabilizing rod is adapted to deform the at least one flexible member when the superior and inferior vertebrae are moved relative to one another within a second range of motion beyond the first range of motion.  
   
   
       54 . A spinal stabilization device, comprising: 
 a first elongate connector adapted to couple to opposed lateral sides of a first vertebra;    a second elongate connector adapted to couple to opposed lateral sides of a second vertebra adjacent to the first vertebra; and    at least one flexible member movably coupled to the first and second elongate connectors such that, when the connectors are mated to adjacent first and second vertebrae, the connectors and the at least one flexible member are effective to allow controlled movement of the adjacent first and second vertebrae.