Expandable fusion device and method of installation thereof
The present invention provides an expandable fusion device capable of being installed inside an intervertebral disc space to maintain normal disc spacing and restore spinal stability, thereby facilitating an intervertebral fusion. In one embodiment, the fusion device includes a central ramp, a first endplate, and a second endplate, the central ramp capable of being moved in a first direction to move the first and second endplates outwardly and into an expanded configuration. The fusion device is capable of being deployed down an endoscopic tube.
1. An expandable intervertebral implant comprising:
a first endplate comprising an upper side, a lower side, a ramped surface extending from the lower side, and a first side portion, wherein the first side portion including a first ramped portion;
a second endplate comprising an upper side, a lower side, a ramped surface extending from the upper side, and a second side portion, wherein the second side portion including a second ramped portion;
a central ramp comprising an expansion portion, the expansion portion having a first ramped surface for engagement with the ramped surface of the first endplate and a second ramped surface for engagement with the ramped surface of the second endplate, the central ramp configured with a blind hole,
a driving ramp comprising an expansion portion and an opening extending though the driving ramp, the expansion portion of the driving ramp configured to engage to the first and second endplates, wherein the opening of the driving ramp extends from a first end of the driving ramp to a second end of the driving ramp and wherein the opening of the driving ramp is unthreaded along its entire length from the first end of the driving ramp to the second end of the driving ramp;
an actuator extending through the opening of the driving ramp and configured to engage with the blind hole in the central ramp,
wherein the actuator is configured to be actuated in one direction to cause at least one of the driving ramp and the central ramp to move in a first direction and cause the first and second endplates to move away from one another to an implant expanded position, and wherein the actuator is configured to be actuated in a second direction to cause at least one of the driving ramp and the central ramp to move in a second direction and cause the first and second endplates to move towards one another to an implant collapsed position, and
wherein the first ramped portion of the first side portion of the first endplate and the second ramped portion of the second side portion of the second endplate are complementary with one another such that the first ramped portion and the second ramped portion abut each other when the implant is in the collapsed position and the first ramped portion of the first side portion of the first endplate and the second ramped portion of the second side portion of the second endplate are positioned closer to the central ramp than the driving ramp in the collapsed position.
2. The expandable intervertebral implant of claim 1 , wherein the first endplate and the second endplate each have a first end and a second end, the first endplate and the second endplate each comprising an upper surface connecting the first end and the second end and a lower surface connecting the first end and the second end.
3. The expandable implant of claim 1 , wherein the central ramp comprises a longitudinally extending extension, the longitudinally extending extension including a threaded opening.
4. The expandable implant of claim 1 , wherein the actuator comprises a head portion, a threaded portion and a connecting portion that connects the head portion and the threaded portion.
5. The expandable implant of claim 1 , wherein the driving ramp includes at least one slot for receiving an insertion instrument.
6. The expandable intervertebral implant of claim 1 , wherein the upper endplate is a single piece and the lower endplates is a single piece and wherein the upper and lower endplates each include an opening extending from the respective upper side to the respective lower side.
7. The expandable intervertebral implant of claim 4 , wherein the head portion of the actuator is retained in the driving ramp.
8. The expandable intervertebral implant of claim 1 , wherein the upper side of the first endplate includes texturing for engaging a vertebral body and the lower side of the second endplate includes texturing for engaging a second vertebral body.
9. The expandable intervertebral implant of claim 1 , wherein the first endplate is slidingly coupled to the central ramp and the driving ramp and the second endplate is slidingly coupled to the central ramp and the driving ramp.
10. An intervertebral implant comprising:
a first endplate comprising an upper side, a lower side, a ramped surface extending from the lower side, and a first side portion, wherein the first side portion including a first ramped portion;
a second endplate comprising an upper side, a lower side, a ramped surface extending from the upper side, and a second side portion, wherein the second side portion including a second ramped portion;
a central ramp comprising an expansion portion, the expansion portion having a first ramped surface for engagement with the ramped surface of the first endplate and a second ramped surface for engagement with the ramped surface of the second endplate, the central ramp configured with an opening,
a driving ramp having a first end and a second end and comprising an expansion portion and an opening extending though the driving ramp, the expansion portion of the driving ramp configured to engage to the first and second endplates;
an actuator extending through the opening of the driving ramp and configured to engage with the opening in the central ramp, wherein the actuator includes a head portion, a threaded portion and a connecting portion between the head portion and the threaded portion, wherein the head portion of the actuator includes a first surface defining an opening configured to receive an actuation instrument,
wherein the actuator is configured to be actuated in one direction to cause at least one of the driving ramp and the central ramp to move in a first direction and cause the first and second endplates to move away from one another to an implant expanded position, and wherein the actuator is configured to be actuated in a second direction to cause at least one of the driving ramp and the central ramp to move in a second direction and cause the first and second endplates to move towards one another to an implant collapsed position, and
wherein the first ramped portion of the first side portion of the first endplate and the second ramped portion of the second side portion of the second endplate are complementary with one another such that the first ramped portion and the second ramped portion nest when the implant is in the collapsed position and the first ramped portion of the first side portion of the first endplate and the second ramped portion of the second side portion of the second endplate are positioned closer to the central ramp than the driving ramp in the collapsed position.
11. The intervertebral implant of claim 10 , wherein the first end of the driving ramp includes a first end surface and wherein the first surface of the head portion of the actuator is coplanar with the first end surface of the first end of the driving ramp.
12. The intervertebral implant of claim 10 , wherein the first endplate and the second endplate each have a first end and a second end, the first endplate and the second endplate each comprising an upper surface connecting the first end and the second end and a lower surface connecting the first end and the second end.
13. The intervertebral implant of claim 10 , wherein the central ramp comprises a longitudinally extending extension, the longitudinally extending extension including a threaded opening.
14. The intervertebral implant of claim 10 , wherein the driving ramp includes at least one slot for receiving an insertion instrument.
15. The intervertebral implant of claim 10 , wherein the upper endplate is a single piece and the lower endplates is a single piece and wherein the upper and lower endplates each include an opening extending from the respective upper side to the respective lower side.
16. The intervertebral implant of claim 10 , wherein the head portion of the actuator is retained in the driving ramp.
17. The intervertebral implant of claim 10 , wherein the upper side of the first endplate includes texturing for engaging a vertebral body and the lower side of the second endplate includes texturing for engaging a second vertebral body.
18. The intervertebral implant of claim 10 , wherein the first endplate is slidingly coupled to the central ramp and the driving ramp and the second endplate is slidingly coupled to the central ramp and the driving ramp.
19. An expandable intervertebral implant comprising:
a first endplate comprising an upper side, a lower side, a ramped surface extending from the lower side, and a first side portion, wherein the first side portion including a first ramped portion;
a second endplate comprising an upper side, a lower side, a ramped surface extending from the upper side, and a second side portion, wherein the second side portion including a second ramped portion;
a central ramp comprising an expansion portion, the expansion portion having a first ramped surface for engagement with the ramped surface of the first endplate and a second ramped surface for engagement with the ramped surface of the second endplate, the central ramp configured with a blind hole,
a driving ramp having a first end and a second end and comprising an expansion portion and an opening extending though the driving ramp, the expansion portion of the driving ramp configured to engage to the first and second endplates, wherein the opening of the driving ramp extends from the first end of the driving ramp to the second end of the driving ramp and wherein the opening of the driving ramp is unthreaded along its entire length from the first end of the driving ramp to the second end of the driving ramp;
an actuator extending through the opening of the driving ramp and configured to engage with the blind hole in the central ramp, wherein the actuator includes a head portion, a threaded portion and a connecting portion between the head portion and the threaded portion, wherein the head portion of the actuator includes a first surface defining an opening configured to receive an actuation instrument,
wherein the actuator is configured to rotate in one direction to cause at least one of the driving ramp and the central ramp to move in a first direction and cause the first and second endplates to move away from one another to an implant expanded position, and wherein the actuator is configured to rotate in a second direction to cause at least one of the driving ramp and the central ramp to move in a second direction and cause the first and second endplates to move towards one another to an implant collapsed position, and
wherein the first end of the driving ramp includes a first end surface and wherein the first surface of the head portion of the actuator is coplanar with the first end surface of the first end of the driving ramp,
wherein the first ramped portion of the first endplate and the second ramped portion of the second endplate are complementary with one another such that the first ramped portion and the second ramped portion nest when the implant is in the collapsed position, and
wherein the first ramped portion of the first side portion of the first endplate and the second ramped portion of the second side portion of the second endplate are positioned closer to the central ramp than the driving ramp in the collapsed position.