Expandable intervertebral implants
Interbody spacers are expandable horizontally and vertically by an application of axial force, and lockable in an expanded configuration. The spacers include support members interconnected to end bodies by pivotable link members. The spacers are introduced between vertebral bodies in a compressed configuration and expanded to fill the intervertebral space and provide support and selective lordotic correction. Graft material may be introduced into the expanded spacer. Provisional and/or supplementary locking means lock the spacers in the expanded configuration. Embodiments of the spacers include symmetrically and asymmetrically configured spacers. Methods of expansion include symmetric expansion or asymmetric expansion along each of two directions.
1. An intervertebral spacer comprising:
a first expandable support member configured to expand in a first direction;
a second expandable support member configured to expand in the first direction;
a first expander coupled to the first expandable support member, wherein the first expander is configured to rotate relative to the first expandable support member to move the first expandable support member away from a longitudinal axis of the intervertebral spacer, and wherein the first expander is configured to slide along the first expandable support member in a second direction different than the first direction to cause expansion of the first expandable support member in the first direction; and
a second expander coupled to the second expandable support member, wherein the second expander is configured to rotate relative to the second expandable support member to move the second expandable support member away from the longitudinal axis of the intervertebral spacer, and wherein the second expander is configured to slides along the second expandable support member in a third direction different than the first direction to cause expansion of the second expandable support member in the first direction.
2. The intervertebral spacer of claim 1 , wherein the second and third directions are substantially parallel to one another.
3. The intervertebral spacer of claim 1 wherein the first direction is generally perpendicular to a transverse plane of the intervertebral spacer.
4. The intervertebral spacer of claim 1 wherein rotation of the first and second expanders relative to the respective first and second expandable support members transitions the intervertebral spacer from a laterally unexpanded configuration to a laterally expanded configuration.
5. The intervertebral spacer of claim 1 wherein sliding of the first and second expanders relative to the first and second expandable support members transitions the intervertebral spacer from a laterally expanded and vertically collapsed configured to a laterally and vertically expanded configuration.
6. The intervertebral spacer of claim 1 wherein, relative to a plane extending along the longitudinal axis, the first expandable support member is bilaterally symmetrical with the second expandable support member and the first expander is bilaterally symmetrical with the second expander.
7. The intervertebral spacer of claim 1 , further comprising:
a first end body coupled to a first end portion of the first and second expandable support members; and
a second end body coupled to a second end portion of the first and second expandable support members, opposite the first end portion, wherein the first end body and the second end body are movable toward one another to cause the intervertebral spacer to move sequentially to different expanded configurations.
8. The intervertebral spacer of claim 7 wherein the different expanded configurations include a laterally expanded configuration and a laterally and vertically expanded configuration.
9. The intervertebral spacer of claim 7 wherein the intervertebral spacer is configured to automatically lock in different expanded configurations.
10. The intervertebral spacer of claim 1 , further comprising a supplementary locking structure configured to hold the intervertebral spacer in a laterally and vertically expanded configuration.
11. The intervertebral spacer of claim 1 wherein the first and second expandable support members transition between—
(i) a laterally collapsed configuration,
(ii) a laterally expanded configuration, and
(iii) a vertically expanded configuration in which, relative to the laterally expanded configuration, the first expandable support member and the second expandable support member each have a second dimension greater than the first dimension.
12. An intervertebral spacer comprising:
a first expandable support member;
a second expandable support member;
a first expander coupled to the first expandable support member, wherein the first expander is configured to rotate relative to the first expandable support member to move the first expandable support member away from a longitudinal axis of the intervertebral spacer, and wherein the first expander slides along the first expandable support member to cause expansion of the first expandable support member; and
a second expander coupled to the second expandable support member, wherein the second expander is configured to rotate relative to the second expandable support member to move the second expandable support member away from the longitudinal axis of the intervertebral spacer, and wherein the second expander slides along the second expandable support member to cause expansion of the second expandable support member.
13. The intervertebral spacer of claim 12 , wherein the first expandable support member is configured to move laterally outward away from each other.
14. The intervertebral spacer of claim 12 wherein the rotation of the first and second expanders relative to the respective first and second expandable support members causes lateral expansion of the intervertebral spacer.
15. The intervertebral spacer of claim 12 wherein the first and second expanders are slidable along the first and second expandable support members to cause the intervertebral spacer to move from a laterally expanded configured to a laterally and vertically expanded configuration.
16. An intervertebral spacer comprising:
a first expandable support member;
a second expandable support member;
a first expander rotatably coupled to the first expandable support member, wherein the first expander is configured to rotate relative to the first expandable support member to move the first expandable support member away from the second expandable support member, and wherein the first expander is configured to slide along and expand the first expandable support member; and
a second expander rotatably coupled to the second expandable support member, wherein the second expander is configured to rotate relative to the second expandable support member to move the second expandable support member away from the second expandable support member, and wherein the second expander is configured to slide along and expand the second expandable support member.
17. The intervertebral spacer of claim 16 , further comprising a threaded member rotatable relative to the first and second expanders to move the first expandable support member and the second expandable support member away from each other.
18. The intervertebral spacer of claim 16 , further comprising a locking threaded member configured to cause deployment of the intervertebral spacer when rotated relative to the first and second expanders, and wherein the locking threaded member is configured to hold the intervertebral spacer in an expanded configuration.