Expandable fusion device and method of installation thereof
The present invention provides an expandable fusion device capable of being inserted between adjacent vertebrae to facilitate the fusion process. A method of installing an expandable fusion device may comprise introducing the expandable fusion device into an intervertebral space, wherein the expandable fusion device comprises a proximal end, a distal end, an anterior side connecting the proximal end and the distal end, and a posterior side connecting the proximal end and the distal end, wherein the expandable fusion device has an anterior height on the anterior side and a posterior height on the posterior side. The method may further comprise adjusting the anterior height of the expandable fusion device independently from adjustment of the posterior height. The method may further comprise adjusting the posterior height of the expandable fusion device.
1. An expandable fusion device comprising:
a first endplate;
a first ramp that is pivotally coupled to the first endplate;
a second endplate;
a second ramp that is pivotally coupled to the second endplate;
a translation member assembly in engagement with the first ramp and the second ramp, the translation member assembly comprising ramps on a first side of the expandable fusion device and ramps on a second side of the expandable fusion device;
a first actuation member in engagement with the translation member assembly on the first side of the expandable fusion device; and a second actuation member in engagement with the translation member assembly on the second side of the expandable fusion device,
wherein the first ramp comprises a first anterior ramp frame and a first posterior ramp frame, and wherein the second ramp comprises a second anterior ramp frame and a second posterior ramp frame.
2. The expandable fusion device of claim 1 , wherein the first side is an anterior side, and wherein the second side is a posterior side.
3. The expandable fusion device of claim 1 , wherein the first anterior ramp is pivotally coupled to the first endplate on the first side of the expandable fusion device, wherein the first posterior ramp is pivotally coupled to the first endplate on the second side of the expandable fusion device.
4. The expandable fusion device of claim 1 , wherein the second anterior ramp is pivotally coupled to the second ramp on the first side of the expandable fusion device, wherein the second posterior ramp is pivotally coupled to the second ramp on the second side of the expandable fusion device.
5. The expandable fusion device of claim 1 , wherein protrusions of the first endplate are engaged with mating features on the first ramp to form pivot points, and wherein protrusions on the second endplate are engaged with mating features on the second ramp to form pivot points.
6. The expandable fusion device of claim 1 , wherein the translation member assembly comprises: an anterior translation portion disposed on the first side of the expandable fusion device, wherein the anterior translation portion comprises one or more ramps; and a posterior translation portion in engagement with the anterior translation portion and disposed one the second side of the expandable fusion device, wherein the posterior translation portion is slidable with respect to the anterior translation portion, wherein the posterior translation portion comprises one or more ramps.
7. The expandable fusion device of claim 6 , further comprising an anterior ramped end disposed on the first side of the expandable fusion device and at a proximal end of the expandable fusion device; and a posterior ramped end in engagement with the anterior ramped end, wherein the posterior ramped end is disposed on the second side of the expandable fusion device and at the proximal end of the expandable fusion device, wherein the posterior ramped end is slidable with respect to the anterior ramped end.
8. The expandable fusion device of claim 7 , wherein the first actuation member comprises an actuation screw threaded through the anterior ramped end to engage the anterior translation portion, wherein rotation of the first actuation member in a first direction causes the anterior ramped end and the anterior translation portion to move towards one another.
9. The expandable fusion device of claim 7 , wherein the second actuation member comprises an actuation screw threaded through the posterior ramped end to engage the posterior translation portion, wherein rotation of the second actuation member in a first direction causes the posterior ramped end and the posterior translation portion to move towards one another.
10. The expandable fusion device of claim 1 , wherein the first actuation member and the second actuation member are independently rotatable to selective adjust anterior height and posterior height of the expandable fusion device.
11. An expandable fusion device comprising:
a first endplate;
a second endplate;
a translation member assembly disposed at least partially between the first endplate and the second endplate, wherein the translation member assembly comprises:
an anterior translation portion disposed on an anterior side of the expandable fusion device, wherein the anterior translation portion comprises one or more ramps;
a posterior translation portion in engagement with the anterior translation portion, wherein the posterior translation portion is disposed on a posterior side of the expandable fusion device, wherein the posterior translation portion is slidable with respect to the anterior translation portion, wherein the posterior translation portion comprises one or more ramps;
an anterior ramped end disposed on the anterior side of the expandable fusion device and at a proximal end of the expandable fusion device; and
a posterior ramped end in engagement with the anterior ramped end, wherein the posterior ramped end is disposed on the posterior side of the expandable fusion device and at the proximal end of the expandable fusion device, wherein the posterior ramped end is slidable with respect to the anterior ramped end;
a first actuation screw threaded through a bore in the anterior ramped end and engaging the anterior translation portion; and a second actuation screw threaded through a bore in the posterior ramped end and engaging the posterior translation portion.
12. The expandable fusion device of claim 11 , wherein the anterior ramped end disposed on the anterior side of the expandable fusion device that engage the ramps in the anterior translation portion to transfer motion of the anterior translation portion to the first endplate and the second endplate thereby pushing the first endplate and the second endplate outward increasing an anterior height of the expandable fusion device and posterior ramp frames disposed on the posterior side of the expandable fusion device that engage the ramps in the posterior translation portion to transfer motion of the posterior translation portion to the first endplate and the second endplate thereby pushing the first endplate and the second endplate outward increasing a posterior height of the expandable fusion device.
13. The expandable fusion device of claim 12 , wherein anterior ramped end comprises a body portion comprising ramps and the bore of the anterior ramped end, and wherein posterior ramped end comprises a body portion and the bore of the posterior ramped end.
14. The expandable fusion device of claim 12 , wherein the anterior ramped end comprise a first anterior ramp frame pivotally coupled to the first endplate and a second anterior ramp frame pivotally coupled to the second endplate.
15. The expandable fusion device of claim 12 , wherein the posterior ramped end comprise a first posterior ramp frame pivotally coupled to the first endplate and a second posterior ramp frame pivotally coupled to the second endplate.
16. A method of installing an expandable fusion device, the method comprising:
introducing the expandable fusion device into an intervertebral space, wherein the expandable fusion device comprises a proximal end, a distal end, an anterior side connecting the proximal end and the distal end, and a posterior side connecting the proximal end and the distal end, wherein the expandable fusion device has an anterior height on the anterior side and a posterior height on the posterior side;
adjusting the anterior height of the expandable fusion device independently from adjustment of the posterior height; and
adjusting the posterior height of the expandable fusion device,
wherein the anterior height is first adjusted prior to adjustment of the posterior height to set a lordotic angle of the expandable fusion device, and wherein the adjustment of the anterior height continues while the posterior height is adjusted.
17. The method of claim 16 , wherein adjusting the anterior height and adjusting the posterior height comprise adjusting separate anterior endplates and posterior endplates.
18. The method of claim 16 , wherein the adjusting the anterior height comprises rotating a first actuation screw to cause ramps on the anterior side of a translation member assembly to engage anterior ramp frames forcing them to push against the anterior side of a first endplate and a second endplate.