Composite material spinal implant
Some embodiments relate to a pedicle screw implant construct kit, comprising: at least one pedicle screw including a head; an embracing structure shaped and sized for embracing at least a portion of the screw head; an upper fastener for mounting onto the embracing structure, the upper fastener having a polygonal profile at least on a face of the upper fastener facing a direction opposite the screw.
1 . A pedicle screw implant construct kit, comprising:
an elongated rod;
a pedicle screw including an integrally formed screw head;
a lower fastener having a proximal end and a distal end, wherein said lower fastener includes a recess extending distally from said lower fastener proximal end, said recess sized and shaped for receiving said elongated rod, and wherein said lower fastener includes a hole extending through said lower fastener;
an embracing structure having an adaptor configured to fit at least partly inside said lower fastener, distal to said elongated rod, said embracing structure defining a recess for a portion of the screw head, wherein said adaptor is formed of two discrete components each including an opposing surface wherein, when positioned inside said lower fastener, said opposing surfaces of said first and second adaptor portions oppose each other; and
a restricting pin configured to extend through said hole, wherein said restricting pin is configured to be directed toward said opposing surfaces of said two discrete adaptor components when extended through said hole and is configured to lock said adaptor at a selected orientation relative to said lower fastener; and
wherein each of the elongated rod, said pedicle screw, said lower fastener, and said adaptor comprises composite material including reinforcing filaments embedded in a polymer matrix.
2 . The pedicle screw implant construct kit according to claim 1 , wherein said kit further including a composite material upper fastener for mounting onto said screw head, proximal to said adaptor, said upper fastener and said adaptor securing said elongated rod to said pedicle screw.
3 . The pedicle screw implant construct kit according to claim 2 , wherein said adaptor has an external surface, wherein said lower fastener includes an internal surface and wherein said upper fastener has wing like extensions that fit in between said external surface of said adaptor and said internal surface of said lower fastener.
4 . The pedicle screw implant construct kit according to claim 2 , wherein said upper fastener includes a socket configured for insertion of a tool thereinto.
5 . The pedicle screw implant construct kit according to claim 1 , wherein said adaptor includes a pair of extensions, and wherein said adaptor has at least one curved portion which matches a curvature of said elongated rod, said at least one curved portion including a pair of curved portions formed on a distal portion of said extension.
6 . The pedicle screw implant construct kit according to claim 1 , wherein said adaptor is configured to be mounted on said screw head.
7 . The pedicle screw implant construct kit according to claim 1 , further comprising one or more tools for locking said elongated rod between said adaptor and said screw head distal end by compression.
8 . The pedicle screw implant construct kit according to claim 1 , wherein said pedicle screw is cannulated.
9 . The pedicle screw implant construct kit according to claim 1 , wherein said adaptor includes a pair of adaptor portions, and wherein said restricting pin is configured to pass between said two adaptor portions.
10 . The pedicle screw implant construct kit according to claim 1 , wherein said lower fastener recess has a longitudinal axis, and wherein said restricting pin is configured to extend through said hole in a direction parallel to said lower fastener recess longitudinal axis.
11 . The pedicle screw implant construct kit according to claim 1 , wherein said recess is sized and shaped for receiving said elongated rod such that said elongated rod directly contacts said lower fastener and extends proximally outside said lower fastener when received therein.
12 . The pedicle screw implant construct kit according to claim 1 , wherein said recess is configured to receive the rod in a position directly above said screw head.
13 . The pedicle screw implant construct kit according to claim 1 , wherein said lower fastener is a single component.
14 . The pedicle screw implant construct kit according to claim 1 , wherein said lower fastener recess has a widest dimension at said lower fastener proximal end.
15 . The pedicle screw implant construct kit according to claim 1 , wherein said lower fastener includes an inner surface sized and shaped to receive an upper fastener such that a portion of the upper fastener is positioned proximal to said elongated rod.
16 . The pedicle screw implant construct kit according to claim 1 , wherein said lower fastener extends proximally relative to said elongated rod.
17 . The pedicle screw implant construct kit according to claim 1 ,
wherein said restricting pin does not contact said pedicle screw head.
18 . A method of assembling pedicle screw implant construct, comprising:
providing a pedicle screw including a screw head and a lower fastener having a proximal end and a distal end, wherein said lower fastener includes a recess extending distally from said lower fastener proximal end, said recess sized and shaped for receiving an elongated rod, wherein said lower fastener includes a hole extending through said lower fastener;
implanting said pedicle screw in a spinal vertebra;
positioning the elongated rod through a passage defined by said recess in said lower fastener;
providing an embracing structure having an adaptor formed of two discrete components each including an opposing surface wherein, when positioned inside the lower fastener, the opposing surfaces of the first and second adaptor portions oppose each other, the adaptor configured to fit at least partly inside said lower fastener, distal to said elongated rod, said embracing structure defining a recess for a portion of the screw head;
locking said adaptor against said elongated rod in said lower fastener recess; and
inserting a restricting pin through said hole and directing the restricting pin toward the opposing surfaces of the two discrete adaptor components when extended through the hole to lock the adaptor at a selected orientation relative to a portion of said lower fastener;
wherein said elongated rod, said pedicle screw, said lower fastener, and said adaptor each comprises composite material including reinforcing filaments embedded in a polymer matrix.
19 . The method of claim 18 , further comprising, following said locking of said adaptor, adjusting a position of said elongated rod by linearly moving said elongated rod within said lower fastener recess.
20 . The method of claim 18 , further comprising, prior to said locking, adjusting an angle of said pedicle screw relative to a long axis defined by said elongated rod.