Articulating and expandable interbody fusions devices
Expandable fusion devices, systems, and methods thereof. The expandable implant may include first and second lateral legs and link plates pivotably joined between them. The lateral legs may include upper and lower endplates configured to engage adjacent vertebrae, an actuator assembly including a rotatable actuator having a shaft and a rotatable nut, and driving ramps positioned along the shaft of the actuator. The actuator assembly may cause independent movement of one or more of the driving ramps, thereby causing an expansion in height of the upper and lower endplates of the lateral legs and passive expansion of the connected link plates.
1. An expandable implant comprising:
an expandable spacer including:
upper and lower endplates configured to engage adjacent vertebrae;
an actuator assembly including a rotatable actuator having a shaft;
a plurality of driving ramps positioned along the actuator shaft, wherein the upper and lower endplates are engaged with the plurality of driving ramps such that actuation of the actuator assembly causes movement of the driving ramps to thereby expand the upper endplate relative to the lower endplate;
a strain gauge embedded in at least one of the endplates and configured to measure force being applied to the expandable implant by a vertebral body,
first and second expandable spacers; and
the expandable implant further comprising a link plate pivotally coupled to the first and second expandable spacers.
2. The expandable implant of claim 1 , wherein the strain gauge includes a plurality of spaced apart strain sensors in a full bridge configuration.
3. The expandable implant of claim 1 , wherein the upper and lower endplates are 3-D printed endplates and the strain gauge is embedded in at least one of the upper and lower endplates 3 .
4. The expandable implant of claim 1 , wherein:
the strain gauge includes a plurality of spaced apart strain sensors;
a circuitry connecting the strain sensors and configured to measure differential pressures across one of the upper and lower endplates from the strain sensors.
5. The expandable implant of claim 1 , wherein the strain gauge includes a plurality of spaced apart strain sensors having a first set of strain sensors and a second set of sensors arranged in a parallel configuration relative to the first set of strain sensors.
6. The expandable implant of claim 1 , wherein the strain gauge includes:
a first set of spaced apart strain sensors embedded in the first expandable spacer;
a second set of spaced apart strain sensors embedded in the second expandable spacer; and
a third set of spaced apart strain sensors embedded in the link plate.
7. An expandable implant comprising:
first and second lateral legs, each including:
upper and lower endplates configured to engage adjacent vertebrae;
an actuator assembly including a rotatable actuator having a shaft and a rotatable nut;
a plurality of driving ramps including a front ramp, a mid-ramp, and a rear ramp positioned along the shaft of the actuator, wherein the upper and lower endplates are engaged with the plurality of driving ramps, and wherein rotation of the actuator and/or the nut causes movement of one or more of the driving ramps, thereby causing an expansion in height of the upper and lower endplates;
at least one link plate pivotably coupled to each of the first and second lateral legs; and
a strain gauge embedded in at least one of the first lateral leg, the second lateral leg, and the link plate, the strain gauge configured to measure force being applied to the expandable implant by a vertebral body.
8. The expandable implant of claim 7 , wherein the strain gauge includes a plurality of sensors and a circuitry connecting the plurality of sensors.
9. The expandable implant of claim 7 , wherein the strain gauge measures the force, pressure, tension, and/or weight distribution across the surface area of the implant.
10. The expandable implant of claim 7 , wherein a first strain gauge is embedded in the upper endplate of the first lateral leg, a second strain gauge is embedded in the upper endplate of the second lateral leg, and a third strain gauge is embedded in the link plate, wherein at least one of the strain gauges has a different circuitry that the other strain gauges.
11. The expandable implant of claim 7 , wherein the first and second lateral legs and the at least one link plate are 3D printed, and the strain gauge is embedded in each of the first and second lateral legs and the at least one link plate during the 3D printing process.
12. The expandable implant of claim 7 , wherein the strain gauge includes a plurality of spaced apart strain sensors in a full bridge configuration.
13. The expandable implant of claim 7 , wherein the upper and lower endplates are 3-D printed endplates and the strain gauge is embedded in at least one of the 3-D printed endplates to provide an integration between a material contacting the vertebral body and the strain gauge sensing the strain on the at least one 3-D printed endplate.
14. The expandable implant of claim 7 , wherein:
the strain gauge includes a plurality of spaced apart strain sensors;
a circuitry connecting the strain sensors and configured to measure differential pressures across the at least one endplate from the strain sensors.
15. The expandable implant of claim 7 , wherein the strain gauge includes a plurality of spaced apart strain sensors arranged in an X configuration.
16. The expandable implant of claim 7 , wherein the strain gauge includes a plurality of spaced apart strain sensors having a first set of strain sensors and a second set of sensors arranged in a parallel configuration relative to the first set of strain sensors.