Pedicle screw based vertebral body stabilization apparatus
A pedicle screw stabilization device comprises a superior and inferior pedicle screw anchor with a shaped memory alloy spacer therebetween.
1 . A pedicle screw based spinal stabilization device, comprising:
a superior pedicle screw;
an inferior pedicle screw; and
a spacer coupled to the superior pedicle screw and inferior pedicle screw, the spacer allows compression and expansion of the vertebral bodies and comprises an elastic portion that dampens compression and expansion of the spacer to provide a relatively gentle stop to motion.
2 . The device of claim 1 , wherein the spacer is constructed from shaped memory alloy.
3 . The device of claim 1 , wherein the elastic portion comprises an accordion shape.
4 . The device of claim 1 , wherein the superior pedicle screw and the inferior pedicle screw each comprise an anchor, wherein the anchor includes a bone engaging surface and a top opposite the bone engaging surface, a channel resides in the anchor extending from the top towards the bone engaging surface, the channel being sized to fit the spacer, and a setscrew is threaded into the channel to lock the spacer in the channel.
5 . The device of claim 1 , wherein the superior pedicle screw and inferior pedicle screw are separated by multiple vertebrae.
6 . The device of claim 2 , wherein the shaped memory alloy is nickel-titanium.
7 . The device of claim 2 , wherein the shaped memory alloy has a first shape and a second shape, the first shape providing a first amount of support and the second shape providing a second amount of support.
8 . The device of claim 1 , wherein the elastic portion spans the entire spacer.
9 . The device of claim 1 wherein, the elastic portion is located substantially midway between the superior pedicle screw and the inferior pedicle screw.
10 . A pedicle screw based spinal stabilization device, comprising:
a superior pedicle screw;
an inferior pedicle screw; and
a spacer coupled to the superior pedicle screw and inferior pedicle screw, at least a portion of the spacer comprising shaped memory alloy that allows expansion and compression of vertebral bodies.
11 . The device of claim 10 , wherein the portion provides motion dampening in both a compression direction and a tension direction.
12 . The device of claim 11 , wherein the portion has an accordion shape.
13 . The device of claim 10 , wherein the portion comprises the entire spacer.
14 . The device of claim 10 , wherein the portion comprises a plurality of portions.
15 . The device of claim 14 , wherein the plurality of portions comprises at least a first portion to dampen compressive motion and at least a second portion to dampen expansive motion.
16 . The device of claim 15 , wherein the first portion and the second portion are different.
17 . The device of claim 1 , further comprising a band coupled to the vertebral bodies.
18 . The device of claim 1 , further comprising a band wherein the band is coupled to the vertebral bodies through the superior pedicle screw and the inferior pedicle screw.
19 . The device of claim 18 , wherein the band comprises shaped memory alloys.
20 . The device of claim 1 , wherein the superior pedicle screw carries a bone growth material.
21 . The device of claim 20 , wherein the inferior pedicle screw carries the bone growth material.
22 . The device of claim 1 , wherein the superior pedicle screw comprises at least one bone growth channel.
23 . The device of claim 22 , wherein the inferior pedicle screw comprises at least one bone growth channel.