Apparatus and method for anterior intervertebral spinal fixation and fusion
View Patent ↗A fixation device including a housing, a shaft and a plurality of blades preloaded onto the shaft. The housing includes a leading deep surface, a trailing outer surface, weight bearing sides, and top and bottom surfaces. The shaft runs from the leading deep surface to the trailing outer surface of the housing. The plurality of blades includes at least one first blade having at least one cutting extension in a first orientation about the axis of the shaft and at least one second blade having at least one cutting extension in a second orientation about the axis of the shaft that is opposite to the first orientation. Each cutting extension of the blades has a sharp leading edge, wherein upon clockwise or counterclockwise rotation of each blade of the plurality of blades about the axis of the shaft in a direction in which the at least one cutting extension of each blade is oriented, the at least one cutting extension of each blade will break an endplate of a vertebra, hook into the vertebra and rigidly secure the vertebra to the device to prevent separation of the vertebra from the device during spinal motion.
1. A fixation comprising:
a housing with a leading deep surface, a trailing outer surface, weight bearing sides, and top and bottom surfaces;
a shaft, having an axis, running from a center of the leading deep surface to a center of the trailing outer surface of the housing; and
plurality of blades preloaded onto the shaft in the housing, at least one first blade having at least one cutting extension in a first orientation about the axis of the shaft and at least one second blade having at least one cutting extension in a second orientation about the axis of the shaft that is opposite to the first orientation, each cutting extension having a sharp leading edge, wherein upon clockwise or counterclockwise rotation of each blade of the plurality of blades about the axis of the shaft in a direction in which the at least one cutting extension of each blade is oriented, the at least one cutting extension of each blade will break an endplate of a vertebra, hook into the vertebra and rigidly secure the vertebra to the device to prevent separation of the vertebra from the device during spinal motion.
2. The device of claim 1 , wherein the housing is configured in a shape of a box, a cylinder or other geometric shape including configurations with a height of the leading deep surface smaller than a height of the trailing outer surface, the shape conforming to a shape of a spinal disk space.
3. The device of claim 1 , wherein the housing is expandable at least in part in vertical and horizontal directions.
4. The device of claim 1 , wherein the housing comprises at least one material of metal, plastic, ceramic, graphite, coral or human bone products.
5. The device of claim 1 , wherein the housing is absorbable.
6. The device of claim 1 , wherein the housing is formed at least in part of a porous material.
7. The device of claim 1 , wherein the shaft comprises a plurality of shafts that serve as axis of rotation to the plurality of blades, the at least one first blade and the at least one second blade are preloaded on different shafts.
8. The device of claim 1 , wherein each blade of the plurality of blades includes two opposing cutting extensions with sharp leading edges configured to hook into adjacent vertebrae to rigidly secure the adjacent vertebrae in relation to each other and to the device to prevent separation of the vertebrae from the device during spinal motion.
9. The device of claim 1 , wherein the blades vary in size to accommodate the configuration of the housing.
10. The device of claim 1 , wherein the blades alternate between the first orientation and the second orientation.
11. The device of claim 1 , further comprising means for rotating each of the plurality of blades from a horizontal into a vertical orientation.
12. The device of claim 1 , wherein the blades are rotated individually or as a group from within the housing.
13. The device of claim 1 , further comprising means for locking the plurality of blades in a final engaged position preventing dislodging from the vertebra.
14. The device of claim 1 , wherein the at least one blade of the plurality of blades includes a body having a shape configured to provide weight bearing support to the secured vertebra through at least one opening of the top and bottom surfaces.
15. The device of claim 14 , wherein the shape of the body is an oval shape configured to expand the disk space as the blade is rotated.
16. The device of claim 1 , wherein the leading deep surface conforms to a posterior aspect of an intervertebral disk and the trailing outer surface conforms to an anterior surface of the intervertebral disk.
17. The device of claim 1 , wherein the housing includes a plurality of openings enabling ingrowth of bone.
18. The device of claim 1 , wherein the shaft runs perpendicular to the leading deep surface of the housing.
19. A method of using a fixation device between two adjacent vertebrae, the method comprising:
providing a fixation device, the fixation device comprising:
a housing with a leading deep surface, a trailing outer surface, weight bearing sides, and top and bottom surfaces;
a shaft, having an axis, running from a center of the leading deep surface to a center of the trailing outer surface of the housing; and
a plurality of blades preloaded onto the shaft in the housing, at least one first blade having at least one cutting extension in a first orientation about the axis of the shaft and at least one second blade having at least one cutting extension in a second orientation about the axis of the shaft that is opposite to the first orientation;
inserting the fixation device between the adjacent vertebrae;
rotating each blade of the plurality of blades about the axis of the shaft in a direction in which the at least one cutting extension of each blade is oriented; and
breaking an endplate of each vertebra with the at least one cutting extension of each blade, hooking into the vertebra and rigidly securing the vertebra to the device to prevent separation of the vertebra from the device during spinal motion.