Systems and methods for flexible spinal stabilization

Abstract

Devices, methods and systems for stabilizing at least a portion of the spinal column are provided. Anchors are engageable to vertebra and a stabilization member is engageable between the anchors. The stabilization member includes an elongate tension member and a compression member in a passage of the tension member.

1 - 53 . (canceled) 
     
     
         54 . A stabilization member comprising:
 a tension member comprising a body including opposite first and second ends and a passage extending between and through the first and second ends;   a compression member positioned within the passage and comprising opposite first and second ends;   a first rigid portion comprising a first enlarged end portion in abutting engagement with each of the first ends and a first stem extending away from the first ends; and   a second rigid portion comprising a second enlarged end portion in abutting engagement with each of the second ends and a second stem extending away from the second ends.   
     
     
         55 . A stabilization member as recited in  claim 54 , wherein the tension member is a tubular shape made by one or more of braiding, weaving, knitting, sewing, extrusion, injection molding, compression molding, casting, bonding, and laminating. 
     
     
         56 . A stabilization member as recited in  claim 54 , wherein the tension member comprises one or more of polymers such as elastomers, plastics, and rubber, synthetic fibers such as polyethylene, polyesters, polyvinyl alcohol, polyaryletherketone, polyetheretherketone, polyurethane, and copolymer of silicone and polyurethane, metals, and ceramics. 
     
     
         57 . A stabilization member as recited in  claim 54 , wherein:
 the compression member is an elastomer that comprises at least one of silicone, polyurethane, polyolefin and hydrogel; and   the rigid portions are more rigid than the compression member.   
     
     
         58 . A stabilization member as recited in  claim 54 , wherein the compression member is positioned within the passage such that the compression member is not attached to the tension member by tensile forces between the compression member and the tension member. 
     
     
         59 . A stabilization member as recited in  claim 54 , wherein the compression member is movable between a first configuration in which a cross section of the compression member is positioned entirely within cross sections of the end portions and a second configuration in which the compression member bulges such that a portion of the cross section of the compression member extends beyond the cross sections of the end portions. 
     
     
         60 . A stabilization member as recited in  claim 54 , wherein each of the end portions comprises a plurality of holes that receive threads extending through at least one of the tension member and the compression member to attach the end portions to at least one of the tension member and the compression member. 
     
     
         61 . A stabilization member as recited in  claim 54 , wherein the end portions are attached to at least one of the tension member and the compression member by fasteners, molding, fusing, or gluing. 
     
     
         62 . A stabilization member as recited in  claim 54 , wherein the first stem comprises a tapered leading end to facilitate percutaneous placement and the second stem comprises a recess to facilitate engagement with an insertion instrument in a predetermined orientation. 
     
     
         63 . A spinal stabilization system for providing stabilization between a first vertebra and a second vertebra comprising:
 a first anchor configured to engage the first vertebra;   a second anchor configured to engage the second vertebra;   a tension member comprising a body including opposite first and second ends and a passage extending between and through the first and second ends;   a compression member positioned within the passage and comprising opposite first and second ends;   a first rigid portion comprising a first enlarged end portion in abutting engagement with each of the first ends and a first stem extending away from the first ends that is positioned in the first anchor; and   a second rigid portion comprising a second enlarged end portion in abutting engagement with each of the second ends and a second stem extending away from the second ends that is positioned in the second anchor.   
     
     
         64 . A spinal stabilization system as recited in  claim 63 , wherein the compression member is configured to resist movement of the first vertebra relative to the second vertebra toward one another by blocking between the first anchor and the second anchor from within a portion of the tension member. 
     
     
         65 . A spinal stabilization system as recited in  claim 63 , wherein the tension member is the only component of the system coupled between the anchors configured to resist movement of the first vertebra and the second vertebra away from one another. 
     
     
         66 . A spinal stabilization system as recited in  claim 63 , wherein:
 the stems are fixed relative to the anchors; and   the compression member and the tension member are configured such that when the stems are fixed relative to the anchors, the system allows limited motion of a spinal motion segment defined by the first and second vertebrae while providing flexible restraint in flexion, extension and rotation.   
     
     
         67 . A spinal stabilization system as recited in  claim 63 , wherein the compression member is movable between a first configuration in which a cross section of the compression member is positioned entirely within cross sections of the end portions and a second configuration in which the compression member bulges such that a portion of the cross section of the compression member extends beyond the cross sections of the end portions. 
     
     
         68 . A spinal stabilization system as recited in  claim 63 , wherein the anchors each include a receiver member comprising spaced apart arms defining a U-shaped passageway, the stems being positioned in the passageways. 
     
     
         69 . A spinal stabilization system as recited in  claim 63 , wherein:
 the anchors each include a receiver member comprising spaced apart arms defining a U-shaped passageway, the stems being positioned in the passageways; and   the system further comprises first and second plugs each comprising a threaded outer surface that mates with a threaded inner surface of one of the receiver members such that the plugs engage the stems to fix the stems relative to the receiver members.   
     
     
         70 . A spinal stabilization system as recited in  claim 63 , wherein the first stem comprises a tapered leading end to facilitate percutaneous placement and the second stem comprises a recess to facilitate engagement with an insertion instrument in a predetermined orientation. 
     
     
         71 . A spinal stabilization system as recited in  claim 63 , wherein the tension member comprises one or more of polymers such as elastomers, plastics, and rubber, synthetic fibers such as polyethylene, polyesters, polyvinyl alcohol, polyaryletherketone, polyetheretherketone, polyurethane, and copolymer of silicone and polyurethane, metals, and ceramics. 
     
     
         72 . A spinal stabilization system as recited in  claim 63 , wherein:
 the compression member comprises an elastomer that comprises at least one of silicone, polyurethane, polyolefin and hydrogel; and   the rigid portions are more rigid than the compression member.   
     
     
         73 . A spinal stabilization system for providing stabilization between a first vertebra and a second vertebra comprising:
 a first anchor configured to engage the first vertebra and comprising a first threaded bone engaging portion and a first receiver member comprising spaced apart arms defining a first U-shaped passageway therebetween;   a second anchor configured to engage the second vertebra and comprising a second threaded bone engaging portion and a second receiver member comprising spaced apart arms defining a second U-shaped passageway therebetween;   a tension member comprising a body including opposite first and second ends and a passage extending between and through the first and second ends;   a compression member positioned within the passage and comprising opposite first and second ends, the compression member comprising an elastomer that comprises one or more of silicone, polyurethane, polyolefin and hydrogel;   a first rigid portion comprising a first enlarged end portion in abutting engagement with each of the first ends and a first stem extending away from the first ends that is positioned in the first passageway, the first stem comprising a tapered leading end to facilitate percutaneous placement, the first rigid portion being more rigid than the compression member;   a second rigid portion comprising a second enlarged end portion in abutting engagement with each of the second ends and a second stem extending away from the second ends that is positioned in the second passageway, the second stem comprising a recess to facilitate engagement with an insertion instrument in a predetermined orientation, the second rigid portion being more rigid than the compression member; and   first and second plugs each comprising a threaded outer surface that mates with a threaded inner surface of one of the receiver members such that the plugs engage the stems to fix the stems relative to the receiver members,   wherein the compression member and the tension member are configured such that when the stems are fixed relative to the receiver members, the system allows limited motion of a spinal motion segment defined by the first and second vertebrae while providing flexible restraint in flexion, extension and rotation.