Method and apparatus for augmenting bone
View Patent ↗An expandable implant system is configured to increase the height of a target bone, for instance that has been subjected to a compression fracture. The expandable implant system includes an implant assembly that can be inserted into the target bone, and subsequently expanded so as to increase the height of the target bone. The expandable implant system further includes an insertion assembly that is configured to create an insertion channel into the target bone, such that the implant assembly can be inserted in a collapsed configuration into the target bone along the insertion channel, and subsequently expanded.
1. An expandable implant system configured to increase the height of a fractured target bone, the expandable implant system comprising:
a primary implant including a primary implant body configured to transition from an insertion configuration into a radially expanded configuration, the primary implant body being elongate along a central axis and including an inner surface that defines an internal void, wherein a first radial direction extends perpendicular to the central axis and a second radial direction extends perpendicular to the central axis and the first radial direction; and
an auxiliary implant configured to be disposed in the internal void of the primary implant body and expanded from a collapsed configuration to a radially expanded configuration, the auxiliary implant defining a central body portion that extends through the central axis, the central body portion having opposed first and second outer end portions spaced from each other along the first radial direction, the auxiliary implant further defining a first node that extends out from the first outer end portion of the central body portion in both the first and second radial directions, and a second node that extends out from the second outer end portion of the central body portion in both the first and second radial directions, each node defining a respective contact surface, the respective contact surfaces configured to abut the inner surface of the primary implant body, wherein the central body portion and the first and second nodes are configured to expand so as to at least partially define at least one pocket that extends between the first and second nodes,
wherein when the auxiliary implant is expanded into its expanded configuration while disposed in the internal void of the primary implant body, the respective contact surfaces of the first and second nodes abut the inner surface of the primary implant body, thereby applying a force to the inner surface of the primary implant body so as to support the primary implant in the expanded configuration,
wherein the auxiliary implant is folded when it is in the collapsed configuration, and
wherein the central body portion defines a first side surface and a second side surface spaced from the first side surface along the second radial direction, the first and second side surfaces extending from the first outer end portion to the second outer end portion, the central body portion defining a width that extends from the first side surface to the second side surface along the second radial direction and a length that extends along the first radial direction, wherein the length is greater than the width, and the width of the central body portion does not decrease along the length from the first outer end portion to the central axis.
2. The expandable implant system as recited in claim 1 , wherein the primary implant body comprises a plurality of linkages so as to define at least one annular row, each of the plurality of linkages defining first and second opposed side portions connected by corresponding first and second end portions, the first and second side portions defining a distance therebetween, such that the distance increases from a first distance to a second distance, the second distance being greater than the first distance when the plurality of linkages are subjected to an expansion force that causes the primary implant body to expand to the expanded configuration.
3. The expandable implant system as recited in claim 2 , wherein the plurality of linkages comprises at least a first and a second link, wherein the side portions of the first link are longer than the side portions of the second link.
4. The expandable implant system as recited in claim 1 , wherein the primary implant body is bent when the primary implant body is in the expanded configuration.
5. The expandable implant system as recited in claim 1 , wherein the primary implant body is substantially symmetrically shaped when the primary implant is in the expanded configuration.
6. The expandable implant system as recited in claim 5 , wherein the primary implant body is substantially cylindrical when the primary implant body is in the expanded configuration.
7. The expandable implant system as recited in claim 1 , further comprising bone stimulating material configured to be inserted into the at least one pocket.
8. The expandable implant system as recited in claim 1 , further comprising a second primary implant and a second auxiliary implant configured to be expanded inside the second primary implant in the target bone at a location adjacent the primary implant and auxiliary implant.
9. The expandable implant system as recited in claim 1 , further comprising an expansion body that is configured to fit into the internal void of the primary implant body when the primary implant is in the insertion configuration, the expansion body further configured to expand when disposed in the internal void of the primary implant body so as to cause the primary implant to expand from its insertion configuration into its expanded configuration.
10. The expandable implant system as recited in claim 9 , wherein the auxiliary implant is located in the internal void of the primary implant body when the expansion body is not in the internal void.
11. The expandable implant system as recited in claim 1 , wherein the auxiliary implant is substantially I-shaped.
12. The expandable implant system as recited in claim 1 , further comprising an insertion assembly configured to insert the primary implant and the auxiliary implant into the target bone, the insertion assembly including a cannulated body and an opening device that fits inside the cannulated body and presents a cutting edge configured to cut through the target bone so as to create an insertion channel in an interior of the target bone.
13. The expandable implant system as recited in claim 12 , wherein the opening device defines a curved distal end configured to create a curved insertion channel in the interior of the target bone.
14. The expandable implant system as recited in claim 12 , wherein the opening device defines a substantially straight distal end configured to create a substantially straight insertion channel in the interior of the target bone.
15. The expandable implant system as recited in claim 1 , wherein the target bone comprises a vertebral body portion of a vertebra.
16. The expandable implant system as recited in claim 1 wherein the auxiliary implant substantially does not stretch when expanded to the expanded configuration from the collapsed configuration.
17. The expandable implant system as recited in claim 1 , wherein each node defines a node distance that extends along the respective contact surface that abuts the inner surface of the primary implant body, wherein the node distance is less than the length of the central body portion.
18. The expandable implant system as recited in claim 1 , wherein each node defines a node dimension that extends along the second radial direction, wherein the node dimension is less than the length of the central body portion.
19. The expandable implant system as recited in claim 1 , wherein the central body portion, the first node, and the second node define an integral auxiliary implant body.
20. The expandable implant system as recited in claim 1 further comprising:
a bone stimulating material configured to be inserted into the at least one pocket when the auxiliary implant is in the expanded configuration in the internal void of the primary implant body.