Expandable interbody implant with lordosis correction
A spinal implant for placement between vertebral bodies includes a first member for engaging one of the vertebral bodies, a second member for engaging an opposing one of the vertebral bodies, and at least one extendable support element for inducing movement of the entire first member away from the second member. The first member is connected to the second member such that the first member moves away from the second member by a larger distance at a first end of the implant than at a second end of the implant. A connecting member may connect the first and second members together at the second end of the implant. The connecting member may include one or more rotatable linkages, or the connecting member may be an extension of one of the first and second members slidably received within a track defined within the other of the first and second members.
1. A spinal implant for placement between first and second vertebral bodies, the spinal implant having a first end portion and a second end portion, the implant comprising:
a first member having a first surface for engaging a first vertebral body, the first member extending between a first terminal end and a second terminal end having a midpoint equidistant from the first and second terminal ends;
a second member having a second surface for engaging a second vertebral body;
at least one extendable support element connected between the first and second members, the extendable support element being actuatable to induce movement of the entire first member away from the second member at both the first and second end portions of the implant;
a connecting member positioned at the second end portion of the implant, the connecting member connected to both the first member and the second member at the second end portion of the implant, the connecting member connected to the first member closer to the second terminal end than the midpoint,
wherein the extendable support element induces movement of the connecting member when the extendable support element induces the movement of the first member away from the second member, the movement of the connecting member guiding the movement of the first member away from the second member by constraining the movement of the first member at the second end of the implant such that the connecting member causes the first member to move away from the second member by a larger distance at the first end portion of the implant than at the second end portion of the implant when the movement of the first member away from the second member is induced by the extendable support element.
2. The spinal implant of claim 1 , wherein the implant has a longitudinal axis extending between the first and second end portions, the connecting member has a longest dimension, and wherein the longest dimension of the connecting member extends at an oblique angle to the longitudinal axis of the implant.
3. The spinal implant of claim 1 , wherein the connecting member is a rotatable linkage having a first end and a second end, the first end of the linkage being pivotably connected to the first member and the second end of the linkage being pivotably connected to the second member.
4. The spinal implant of claim 1 , wherein the connecting member is an extension of the first member, the extension being slidably received within a track defined within the second member.
5. The spinal implant of claim 1 , wherein the connecting member is configured such that the first member rotates about a point spaced apart from the implant proximate the second end portion of the implant.
6. The spinal implant of claim 1 , wherein the extendable support element is positioned intermediate the first and second end portions of the implant.
7. The spinal implant of claim 6 , wherein the extendable support element is rigidly mounted to the second member at an oblique angle with respect to the second surface.
8. The spinal implant of claim 6 , wherein the extendable support element is configured to be extended by a fluid.
9. The spinal implant of claim 6 , wherein the extendable support element is rigidly mounted to the second member, and wherein the extendable support element is connected to the first member by a pivotable connection, such that the first member can pivot with respect to the extendable support element.
10. The spinal implant of claim 6 , wherein:
the extendable support element is rigidly mounted to the second member, and wherein the extendable support element slidably engages the first member, and
the extendable support element slidably engages the first member along mating curved surfaces.
11. The spinal implant of claim 1 , further comprising at least one post extending between the first member and the second member, the post constraining a maximum movement of the first member away from the second member.
12. The spinal implant of claim 11 , wherein the at least one post is positioned proximate the first end portion of the implant, such that the post constrains the maximum movement of the first member away from the second member at the first end portion.
13. The spinal implant of claim 1 , wherein the first end portion of the implant is at a distal end of the implant and the second end portion of the implant is at a proximal end of the implant, the implant having a longitudinal axis extending between the distal and proximal ends.
14. The spinal implant of claim 13 , wherein the implant includes a connector at the second end portion of the implant, the connector being structured to securely engage an inserter for positioning the implant.
15. The spinal implant of claim 1 , wherein the implant extends along a longitudinal axis between a distal end and a proximal end of the implant, and wherein the first end portion of the implant is positioned on one side of the longitudinal axis and the second end portion of the implant is positioned on an opposing side of the longitudinal axis from the first end portion.
16. The spinal implant of claim 15 , wherein the implant includes a connector at the proximal end of the implant, the connector being structured to securely engage an inserter for positioning the implant.
17. The spinal implant of claim 15 , wherein the at least one extendable support element comprises a first extendable support element and a second extendable support element, the first and second extendable support elements being spaced apart along the longitudinal axis of the implant.
18. A spinal implant for placement between first and second vertebral bodies, the spinal implant having a first end portion and a second end portion, the implant comprising:
a first member having a first surface for engaging a first vertebral body, the first member extending between a first terminal end and a second terminal end having a midpoint equidistant from the first and second terminal ends;
a second member having a second surface for engaging a second vertebral body;
one or more extendable support elements connected between the first and second members, all of the one or more extendable support elements being actuatable by extending at the same rate as one another between the first and second members to induce movement of the entire first member away from the second member at both the first and second end portions of the implant;
a connecting member positioned at the second end portion of the implant, the connecting member connected to both the first member and the second member at the second end portion of the implant, the connecting member connected to the first member closer to the second terminal end than the midpoint, the connecting member configured to guide the movement of the first member away from the second member by constraining the movement of the first member at the second end portion of the implant so as to cause the first member to move away from the second member by a larger distance at the first end portion of the implant than at the second end portion of the implant when the movement of the first member away from the second member is induced by the one or more extendable support elements.
19. A spinal implant for placement between first and second vertebral bodies, the spinal implant having a first end portion and a second end portion, the implant comprising:
a first member having a first surface for engaging a first vertebral body, the first member extending between a first terminal end and a second terminal end having a midpoint equidistant from the first and second terminal ends;
a second member having a second surface for engaging a second vertebral body;
at least one extendable support element connected between the first and second members, the extendable support element being actuatable such that one of the at least one extendable support elements alone induces movement of the entire first member away from the second member;
a connecting member positioned at the second end of the implant, the connecting member connected to both the first member and the second member at the second end portion of the implant, the connecting member connected to the first member closer to the second terminal end than the midpoint, the connecting member configured to guide the movement of the first member away from the second member such that, when the movement of the first member away from the second member is induced by the extendable support element, the first member moves away from the second member by a larger distance at the first end portion of the implant than at the second end portion of the implant,
wherein the connecting member is a rotatable linkage having a first end and a second end, the first end of the linkage being pivotably connected to the first member and the second end of the linkage being pivotably connected to the second member.
20. The spinal implant of claim 19 , wherein when the rotatable linkage rotates with respect to both the first member and the second member when the first member moves away from the second member.