Expandable implant with an integrated deployable retention spike

Abstract

To provide: an expandable fusion device which can be inserted between adjacent vertebra and is configured to be integrated to prevent expulsion of the device; a system; and a method.SOLUTION: An expandable fusion device 200 includes one or more integrated deployable retention spikes 38, 42 configured to resist expulsion of the device when installed in the intervertebral disc space. The implant may include: upper and lower main endplates 12, 14; an actuator assembly configured to cause expansion in height of the upper and lower main endplates; and a sidecar assembly including a sidecar carrier 34, an upper carrier endplate engaged with an upper spike, and a lower carrier endplate engaged with a lower spike so that forward translation of the sidecar carrier pushes against the upper and lower carrier endplates, thereby deploying the upper and lower spikes.SELECTED DRAWING: Figure 19

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This patent application is a continuation - in - part of U.S. Patent Application No. 17 / 540,381, filed on December 2, 2021, which is hereby incorporated by reference in its entirety for all purposes.

[0002] (Field of the Invention) The present disclosure relates to surgical devices, and more particularly to an expandable fixation device that can be inserted between adjacent vertebrae to facilitate a fixation process and includes an integrated deployable retention spike configured to prevent device expulsion.

Background Art

[0003] Sagittal imbalance with one or more spinal cord lesions is often treated by a combination of direct and indirect decompression. Indirect decompression can be achieved by the placement of intervertebral cages. A combination of posterior element osteotomy, placement of the cage(s), and subsequent compression onto a pedicle screw / rod construct can be used to restore segmental lordosis to the surgical level and thus restore the sagittal balance in that region.

[0004] Central line sacrificing discectomy includes osteotomy of the posterior elements and the yellow ligament and creating a wide passage to the underlying dural sac and disc space. An osteotome can be used to remove the posterior spinous process and disc together. The anterior longitudinal ligament (ALL) is released via a spreader or blunt dissection, and bilateral expandable cages are placed on the posterior lumbar interbody fusion (PLIF) trajectory. The rod is reduced onto the screws placed prior to the osteotomy, and the screws are compressed. As the screws are brought closer together, the vertebral body pivots about the fulcrum formed by the intervertebral spacer, increasing the segmental lordosis and resulting in the desired correction.

[0005] Due to the corrective nature of the procedure, a highly adjustable lordosis-expandable cage is required. Cages with a high lordosis profile may have an increased risk of anterior expulsion due to the increased forces in the axial plane. Resection of the anterior longitudinal ligament eliminates the natural barrier that prevents anterior expulsion from the disc space. Therefore, an expandable fixation device incorporating one or more anti-expulsion features is needed. SUMMARY OF THE INVENTION

[0006] To meet this and other needs, and in view of that purpose, the present application provides a device, system, and method for installing and expanding an intervertebral implant and deploying an integrated retention spike. The expandable implant may include one or more integrated retention spikes configured to deploy from the implant body to resist expulsion of the implant from the disc space. Additionally, the expandable intervertebral implant may be configured to communicate implant information with a robotic and / or navigation system. For example, the position and orientation of the implant may be communicated to the system. The implant may include internal electronic components configured to automatically adjust the height / or anterior curve of the implant and deploy the retention spikes. One or more of these features may help minimize the size of the working corridor and the number of instruments required to manipulate the implant.

[0007] According to one embodiment, the expandable implant includes upper and lower main endplates, an actuator assembly, and a sidecar assembly. The upper and lower main endplates are configured to engage adjacent vertebrae. The actuator assembly is configured to cause expansion of the height of the upper and lower main endplates. The sidecar assembly may include a sidecar carrier, an upper carrier endplate pivotally coupled to an upper spike, and a lower carrier endplate pivotally coupled to a lower spike. Forward translation of the sidecar carrier pushes the upper and lower carrier endplates, thereby deploying the upper and lower spikes.

[0008] The expandable implant may include one or more of the following features. The upper carrier end plate may include a first tusk, and the lower carrier end plate may include a second tusk. The first and second tusks may extend toward the front of the implant. The first and second tusks may be receivable within respective passages in the upper and lower main end plates, thereby guiding translation of the upper and lower carrier end plates. The first and second tusks may have a generally polygonal cross-section corresponding to the shape and dimensions of the respective passages. The first and second tusks may allow translation of the upper and lower carrier end plates relative to the main end plates along the main longitudinal axis of the implant, but limit all other translations and rotations. Each spike may extend from a proximal end coupled to a respective carrier end plate to a free end. The free end may be sharp or pointed and may be configured to penetrate bone. Each of the upper and lower main end plates may include a lateral extension defining a side channel. The side channels may be capable of receiving and guiding an upper spike and a lower spike, respectively. Each spike may be connected to a respective carrier end plate using a pin, thereby providing a hinge connection between the carrier end plate and the spike. As the carrier end plate moves forward, the spike may bottom out on the floor of the channel and rotate about the axis of the pin connecting the spike to the carrier end plate, and the spike may emerge from the upper and lower surfaces of the main end plate.

[0009] According to another embodiment, an expandable implant includes upper and lower end plates, an actuator assembly, a plurality of drive ramps, and a sidecar assembly. The upper and lower main end plates are configured to engage adjacent vertebrae. The actuator assembly includes a rotatable actuator having a shaft and a rotatable nut. The plurality of drive ramps includes a front ramp, an intermediate ramp, and a rear ramp disposed along the shaft of the actuator. The upper and lower main end plates are engaged with the plurality of drive ramps. Rotation of the actuator and / or the nut causes movement of one or more of the drive ramps, thereby causing expansion of the height of the upper and lower main end plates. The sidecar assembly includes a sidecar carrier, an upper carrier end plate pivotally coupled to an upper spike, and a lower carrier end plate pivotally coupled to a lower spike. Forward translation of the sidecar carrier pushes the upper and lower carrier end plates, thereby deploying the upper and lower spikes.

[0010] The expandable implant may include one or more of the following features. The rearward inclined portion can include a bore for receiving the actuator assembly and a pair of arms disposed on both sides of the bore. The rearward inclined portion can include a double-tail slot along the outer surface of one of the arms. The sidecar carrier can include a corresponding double-tail that mates with the double-tail of the rearward inclined portion, allowing the sidecar carrier to translate relative to the rearward inclined portion along the major longitudinal axis of the implant while restricting all other translations or rotations. The double-tail slot may decrease in height toward the rear of the rearward inclined portion. The rearward inclined portion can include a retaining tab configured to prevent the retraction of the spike by preventing the movement of the sidecar carrier. The retaining tab may be defined by a relief cut such that the retaining tab projects outwardly from the side surface of the rearward inclined portion. When the sidecar carrier passes over the retaining tab, the retaining tab rises upwardly and prevents the sidecar carrier from moving rearward. Each of the upper main end plate and the lower main end plate may include a lateral extension portion that defines a side channel. The side channel can receive and guide the upper spike and the lower spike, respectively. When the sidecar carrier translates forward, the carrier end plate moves forward, the spike bottoms out on the floor of the channel, rotates the spike, and drives it outwardly from the upper and lower surfaces of the main end plate.

[0011] According to another embodiment, an expandable implant includes upper and lower main end plates, an actuator assembly, and integrated retention spikes. The upper and lower main end plates are configured to engage adjacent vertebrae. The actuator assembly includes a rotatable actuator and drive ramps disposed along the actuator configured to expand the height of the upper and lower main end plates. The integrated retention spikes are deployable from the upper and lower main end plates. The integrated retention spikes deploy when the sidecar carriers are translated forward and push upper and lower carrier end plates pivotally coupled to respective retention spikes. The front and rear heights of the implant may be independently adjustable for continuous adjustment of height and lordotic profile. The retention spikes can maintain a constant penetration depth from the upper and lower main end plates regardless of height or lordotic expansion.

[0012] According to another embodiment, an autonomously expandable implant includes a computing unit, upper and lower main end plates, a plurality of force sensors, an actuation assembly, a plurality of drive ramps, an electric motor, and a power source. The computing unit includes a processor having a memory housed within the implant. The upper and lower main end plates are configured to engage adjacent vertebrae. The plurality of force sensors are housed within the upper and lower main end plates. The force sensors are configured for load distribution measurement. The actuation assembly includes a rotatable actuator having a shaft and a rotatable nut. The plurality of drive ramps are disposed along the actuator's shaft and engage the upper and main end plates. The electric motor is configured to rotate the actuator and / or the nut to move the drive ramps and expand the upper and lower main end plates. The power source is configured to supply power to the electric motor.

[0013] Self-expanding implants may include one or more of the following features. The implant may further include a sidecar assembly including a sidecar carrier, an upper carrier end plate pivotally coupled to an upper spike, and a lower carrier end plate pivotally coupled to a lower spike. Forward translation of the sidecar carrier pushes the upper and lower carrier end plates, thereby deploying the upper and lower spikes. The implant may further include a linear motor configured to translate the sidecar carrier, thereby deploying the upper and lower spikes. The computing unit may be able to automatically notify the linear motor of the drive start and duration for deploying the upper and lower spikes. The plurality of drive ramps may include a front ramp, an intermediate ramp, and a rear ramp disposed along the shaft of the actuator. The implant may further include a plurality of hall effect sensors located within the front and intermediate ramps configured to provide real-time position information of the implant to a robotic navigation system. The computing unit may be able to automatically notify the electric motor of the drive amount and duration to adjust the height and anterior curvature of the implant based on information obtained from the force sensors. The implant may further include a wireless communication unit configured to transmit and receive information to and from a robotic navigation system. The power supply may include a wireless charging receiver, and the insertion instrument may include a wireless charger configured to interface with the wireless charging receiver to supply power to the implant.

[0014] According to another embodiment, the self-expanding implant includes a housing, a computing unit, an upper main end plate and a lower main end plate, a plurality of force sensors, an actuator assembly, a plurality of drive ramps, a pair of electric motors, a sidecar assembly, a linear motor, and a power source, and includes a front nose and a rear end. The computing unit includes a processor having a memory disposed within the housing. The upper and lower main end plates are configured to engage adjacent vertebrae. The plurality of force sensors are housed within the upper and lower main end plates. The force sensors are configured for load distribution measurement. The actuator assembly includes a rotatable actuator having a shaft and a rotatable nut. The plurality of drive ramps are disposed along the shaft of the actuator and include a front ramp, an intermediate ramp, and a rear ramp that engage the upper and lower main end plates. The pair of electric motors are configured to rotate the actuator and the nut independently to move the drive ramps and expand the upper and lower main end plates. The sidecar assembly includes a sidecar carrier, an upper carrier end plate pivotally coupled to an upper spike, and a lower carrier end plate pivotally coupled to a lower spike. The linear motor is configured to translate the sidecar carrier, thereby deploying the upper and lower spikes. The power source is configured to supply power to motors disposed within the implant.

[0015] The self-expanding implant may include one or more of the following features. The linear motor may be disposed behind the sidecar carrier within the housing. The implant may further include a plurality of hall effect sensors configured to provide real-time position information of the implant to a robotic navigation system. The hall effect sensors may be disposed on the front ramp and the intermediate ramp. The computing unit may be disposed on the rear ramp. The implant may further include a wireless communication unit disposed within the housing. The wireless communication unit may be configured to transmit and receive information to and from the robotic navigation system.

[0016] According to yet another embodiment, a system for autonomously controlling an expandable implant includes a robotic navigation system and an inserter. The expandable implant may include a computing unit, upper and lower main end plates, a plurality of force sensors, an actuator assembly, a plurality of drive ramps, an electric motor, a sidecar assembly, a linear motor, and a power source. The computing unit includes a processor having a memory housed within the implant. The upper and lower main end plates are configured to engage adjacent vertebrae. The plurality of force sensors are housed within the upper and lower main end plates. The force sensors are configured for load distribution measurement. The actuator assembly includes a rotatable actuator having a shaft and a rotatable nut configured to cause expansion of the height of the upper and lower main end plates. The plurality of drive ramps are disposed along the shaft of the actuator and engaged with the upper and lower main end plates. The electric motor is configured to rotate the actuator and / or the nut to move the drive ramps and expand the upper and lower main end plates. The sidecar assembly includes a sidecar carrier, an upper carrier end plate pivotally coupled to an upper spike, and a lower carrier end plate pivotally coupled to a lower spike. The linear motor is configured to move the sidecar carrier, thereby deploying the upper and lower spikes. The power source is configured to supply power to the motors. The robotic navigation system includes a movable end effector and a display. The inserter is positionable within the end effector and configured to hold the expandable implant. The robotic navigation system can include a wireless receiver for receiving force and position information of the implant and a wireless transmitter for transmitting user input to the implant. The inserter may include an electromagnet and a wireless charger. The power source may include a wireless charging receiver, and the wireless charger of the inserter may interface with the wireless charging receiver to supply power to the implant. The electromagnet on the inserter can generate an electric field that causes the Hall effect sensor to detect the relative position of the drive ramp.

[0017] According to yet another embodiment, a method of adjusting the height and / or lordosis of an expandable implant and deploying integrated retention spikes may include one or more of the following steps in any suitable order: (1) preparing an intervertebral disc space, including, for example, performing a discectomy; (2) inserting an endoscope tube into the intervertebral disc space; (3) introducing an expandable implant into the intervertebral space in a folded configuration through the tube and seating it in an appropriate position within the intervertebral space; (4) deploying the retention spikes by translating a sidecar carrier toward the front end of the implant, thereby deploying the spikes; (5) expanding the height and / or lordosis of the implant to an expanded position, either before or after deploying the spikes. In the case of an autonomous implant, the method may also include: (6) obtaining load distribution information from force sensors within the endplates; (7) applying a magnetic field to hall effect sensors within the intermediate and anterior inclines, for example, using an electromagnet on an inserter, to determine the physical positions of the endplates and the implant; (8) supplying power to a wireless power receiver within the implant, for example, using a wireless charger on the inserter; (9) expanding the height of the implant and / or adjusting the lordosis using information from a computing unit and / or a robot / navigation system within the implant to operate a DC motor within the implant to drive an internal actuator within the implant; (10) deploying the retention spikes by operating a linear servo motor within the implant using information from a computing unit and / or a robot / navigation system within the implant to move the sidecar carrier and deploy the spikes.

[0018] According to another embodiment, the expandable implant includes upper and lower main end plates configured to engage adjacent vertebrae, an actuator assembly, and a sidecar assembly. At least one of the upper and lower main end plates defines a curved channel and a linear channel. The actuator assembly is configured to cause an expansion of the height of the upper and lower main end plates. The sidecar assembly includes a sidecar carrier and a carrier end plate with a pusher engageable with a spike. The spike is positionable through the curved channel, and the pusher is receivable within the linear channel. A forward translation of the sidecar carrier is configured to deploy the spike.

[0019] The expandable implant may include one or more of the following features. The curved channel and the linear channel may overlap such that the curved channel intersects the linear channel. The linear channel may be a blind channel extending along the longitudinal axis of the implant, and the curved channel may arc outwardly toward the outer surface of the upper or lower main end plate. In the retracted position, the spike may be retained inside the curved channel, and as the sidecar carrier translates forward, the spike moves through the curved channel and extends therefrom, and the pusher follows the linear channel. The spike extends from a proximal end to a free end, and a movable joint may connect the proximal end of the spike to the distal end of the pusher. The movable joint may include a convex base such that the proximal end of the spike is receivable within a corresponding pocket in the pusher, and the pocket may be a pivotable joint to allow the convex base to move along a vertical axis to deploy the spike. The movable joint may be a ball (e.g., partial sphere or full sphere) socket joint.

[0020] According to yet another embodiment, an expandable implant includes upper and lower main endplates configured to engage adjacent vertebrae, an actuator assembly configured to cause an expansion in the height of the upper and lower main endplates, and a sidecar assembly including a carrier endplate having a pusher engaged with a sidecar carrier and spikes. The spikes include a convex base captured within a pocket defined at the free end of the pusher. Forward translation of the sidecar carrier is configured to translate the carrier endplate and deploy the spikes.

[0021] The expandable implant may include one or more of the following features. The pocket may allow the convex base to move vertically along the vertical axis as the spike is pushed forward, rotated, and translated to the deployed position. The pocket may allow the spike to rotate about an axis that coincides with the radius of curvature of the spike. The convex base may be rounded or non-spherical. The bottom surface of the spike may define a slot, and the slot may form a downward hook on the convex base. The pocket may be undercut such that the tip of the pusher forms an upward hook. The upward hook of the pusher may be receivable within the slot of the spike, and the downward hook of the convex base may be receivable within the pocket of the pusher. The actuator assembly can include a rearward ramp having a pair of parallel dovetail slots, and the sidecar carrier can include corresponding dovetails that mate with the dovetail slots of the rearward ramp, allowing the sidecar carrier to translate relative to the rearward ramp along the main longitudinal axis of the implant while restricting all other translations or rotations.

[0022] According to another embodiment, a method of installing an expandable implant may include one or more of the following steps in any suitable order. (1) Inserting an expandable implant into the intervertebral space between adjacent vertebrae, the implant having an upper and lower main endplate, an integrated retaining spike deployable from the upper and lower main endplates, and a sidecar carrier assembly having a translatable sidecar carrier for deploying the integrated retaining spike; (2) Moving an actuator assembly within the expandable implant to cause expansion of the height of the upper and lower main endplates; and (3) Deploying the integrated retaining spike by translating the sidecar carrier, thereby extending the retaining spike from the upper and lower endplates. The retaining spikes may be curved along their lengths with a certain curvature, and the spikes may rotate about the center of curvature of the spikes themselves. The retaining spikes may be capable of moving only vertically along a vertical axis. The retaining spikes can maintain a certain penetration depth from the upper and lower main endplates regardless of height or lordotic expansion.

[0023] Also provided is a kit including various types and sizes of expandable fixation devices, rods, fasteners or anchors, k-wires, dilators and other tools and instruments, robots and / or navigation systems, and other components.

Brief Description of the Drawings

[0024] A more complete understanding of the present invention, and its attendant advantages and features, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings.

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[0025] Embodiments of the present disclosure generally relate to expandable intervertebral implants, systems, and methods. Specifically, embodiments relate to an expandable intervertebral implant having an integrated retaining spike configured to deploy from an implant body to resist expulsion of the implant from an intervertebral disc space. The expandable intervertebral implant may be configured to communicate implant information with a robotic and / or navigation system. For example, the position and orientation of the implant may be communicated as the implant expands. Additionally, the implant may be configured to automatically adjust its height and lordosis and to deploy the retaining spike using internal electronic components. These features can minimize the size of the working access and the number of instruments required to manipulate the implant. The terms implant, intervertebral, intervertebral implant, fixation device, spacer, and expandable device may be used interchangeably herein.

[0026] Referring now to FIGS. 1 - 14, an expandable intervertebral implant 10 according to one embodiment is shown. The expandable intervertebral implant 10 includes an expandable intervertebral spacer having integrally formed deployable retention spikes 16, 18. The expandable implant 10 may include a first major or upper endplate 12, a second major or lower endplate 14, a first or upper deployable spike 16, and a second or lower deployable spike 18. The upper and lower spikes 16, 18 are configured to be deployed by a sidecar assembly 32, which may include a sidecar carrier 34 configured to move an upper carrier endplate 36 coupled to an upper anchor or spike 38 and a lower carrier endplate 40 coupled to a lower anchor or spike 42. The main upper and lower endplates 12, 14 and the upper and lower carrier endplates 36, 40 are configured to be expanded by an actuator assembly 20, which may include a forward ramp 22, an intermediate ramp 24, and a rearward ramp 26 movable via an actuator or central drive screw 28 and an outer drive screw or nut 30.

[0027] The anterior and posterior heights of the implant 10 may be independently adjustable for continuous adjustment of height and lordosis profile. The retention spikes 16, 18 maintain a constant penetration depth from the implant endplates 12, 14 regardless of height or lordotic expansion. The retention spikes 16, 18 may be deployed prior to implant expansion by pushing the sidecar carrier 34 forward and driving the spikes 16, 18 through channels 110 in the main implant endplates 12, 14. When the sidecar carrier 34 advances to its final forward position, the retention tab 132 is no longer depressed, locking the carrier 34 in the forward position. The carrier endplates 36, 40 engage the main endplates 12, 14 and follow their movement through height and lordotic expansion.

[0028] The implant 10 has a nose or front end 46 configured to be initially inserted into the disc space between adjacent vertebral bodies and a rear end or back end 48 configured to be coupled to an instrument for insertion and / or actuation of the actuator assembly 20. In one embodiment, the expandable implant 10 is configured to be disposed within the disc space down an endoscopic tube during a minimally invasive surgical (MIS) procedure. The expandable implant 10 may be inserted in a folded or collapsed position and then expanded in height and / or lordosis. The anchors or spikes 38, 42 may be deployed into adjacent vertebral bodies to provide stability and prevent expulsion from the disc space.

[0029] The expandable fixation device 10 and its components can be manufactured from a number of biocompatible materials such as, but not limited to, titanium, stainless steel, titanium alloys, non-titanium metal alloys, polymeric materials, plastics, plastic composites, PEEK, ceramics, and elastic materials.

[0030] The main upper and lower end plates 12, 14 and the upper and lower carrier end plates 36, 40 are configured to engage adjacent vertebrae. As best seen in FIG. 1, the upper end plate 12 and the upper carrier end plate 36 are both nested together to form the entire upper end plate of the device 10. Similarly, the lower end plate 14 and the lower carrier end plate 40 are both nested together to form the entire lower end plate of the device 10. As best seen in FIG. 11, the upper end plates 12, 36 and the lower end plates 14, 40 are also configured to be nested together or engage in a folded position such that the overall height of the implant is minimized in the folded position. A more detailed description of the upper end plate 12 and the upper carrier end plate 36 will be provided, but it will be understood that this description applies equally to the lower end plate 12 and the lower carrier end plate 40.

[0031] The upper end plate 12 can include an upper or outer surface 50 configured to contact bone and a lower or inner surface 52 opposite the outer surface 50. The outer surface 50 can include a plurality of teeth, ridges, gripping or capturing protrusions, keels, or other texturing or friction-increasing elements to assist in gripping adjacent vertebral bodies. The inner surface 52 can define one or more inclined portions 54 configured to slidably engage with one or more corresponding inclined portions 84, 86, 88 on the anterior inclined portion 22, the intermediate inclined portion 24, and / or the posterior inclined portion 26, thereby providing an expansion of the height of the end plates 12, 14. The end plate 12 may define a through-opening 56 extending between or partially within the outer surface 50 and the inner surface 52. The through-opening 56 may be configured to receive a bone graft or similar bone growth-inducing material to further facilitate and ease intervertebral fixation.

[0032] As best seen in FIG. 2, with the sidecar carrier assembly 32 omitted for clarity, the end plate 12 defines an extension portion 90 near the front end 46 of the end plate 12. The extension portion 90 is a side protrusion that projects outwardly on one side of the end plate 12, thereby increasing the installation area of the device 10. The extension portion 90 defines a recessed region 92 on the side of the device 10 near the rear end 48. The recessed region 92 is sized and dimensioned to receive the body of the upper carrier end plate 36. Although the right side extension portion 90 and recess 92 for receiving the upper carrier end plate 36 are shown, it will be understood that the extension portion 90 and recess 92 may be provided on the opposite side.

[0033] As best seen in FIG. 7, the upper carrier end plate 36 includes a body having an upper or outer surface 94 configured to contact bone and a lower or inner surface 96 opposite the outer surface 94. The outer surface 94 can include one or more teeth, ridges, gripping or capturing protrusions, keels, or other texturing or friction-increasing elements to assist in gripping adjacent vertebral bodies. The inner surface 96 can define one or more inclined portions 98 configured to slidably engage with one or more corresponding inclined portions 24 and / or 86, 100 on the intermediate inclined portion 24 and / or the sidecar carrier 34, thereby providing an expansion of the height of the carrier end plates 36, 40 in cooperation with the upper and lower main end plates 12, 14.

[0034] Turning more particularly to FIG. 4, the upper and lower end plates 12, 14 and the upper and lower carrier end plates 36, 40 are configured to be expanded by an actuator assembly 20, which is configured to move a plurality of drive inclined portions 22, 24, 26 to expand the height of the end plates 12, 14 and the upper and lower carrier end plates 36, 40. The actuator assembly 20 can include a forward inclined portion 22, an intermediate inclined portion 24, and a rearward inclined portion 26 that are movable via an actuator or central drive screw 28 and an outer drive screw or nut 30. The forward inclined portion 22 can include a central longitudinal bore 58, the intermediate inclined portion 24 can include a central longitudinal bore 60, and the rearward inclined portion 26 can include a central longitudinal bore 62. The plurality of drive inclined portions 22, 24, 26 can be positioned along the length of the actuator 28 and are each configured to engage and drive the upper and lower end plates 12, 14. When one or more of the drive inclined portions 22, 24, 26 are moved, they slide relative to the upper and lower end plates 12, 14 and / or the upper and lower carrier end plates 36, 40, thereby providing an expansion of the height. The expansion can include the ability to individually adjust the forward and / or rearward height of the end plates 12, 14.

[0035] The implant 10 includes an expansion assembly 20. The expansion platform includes two main end plates 12, 14, both of which are symmetrically interlocked with rear, intermediate, and front inclines 22, 24, 26, such that the front incline 22 is coaxially aligned along the axis of the central drive screw 28 so as to be translationally fixed along the axis of the central drive screw 28 via a front lock nut 77 and a front bushing 102. The rear incline 24 and the intermediate incline 26 are free to translate along the axis of the central drive screw 28, and the intermediate incline 24 is driven by the rotation of the central drive screw 28. The central drive screw 28 is concentrically disposed within an outer drive screw 30, is free to translate along the axis of the outer drive screw 30, and can be driven by the outer drive screw 30. The outer drive screw 30 is seated within an axial bore 62 of the rear incline 26 and is translationally fixed relative to the rear incline 26 via a rear lock nut 104. The bushing 106 can function as a bearing surface for rotational movement. The relative movement of the front incline 22 and the intermediate incline 24 can expand and contract the main end plates 12, 14 such that the front height and the rear height change at the same rate. The relative movement of the front incline 22 and the rear incline 26 can expand the main end plates 12, 14 such that the rear height decreases and the front height increases.

[0036] The actuation assembly 20 is configured to independently expand the respective heights of the end plates 12, 14 and the associated upper and lower carrier end plates 36, 40. The actuation assembly 20 includes a rotatable actuator or central drive screw 28 configured to move a plurality of internal inclines 22, 24, 26, and a rotatable nut or outer drive screw 30. The three drive inclines, namely the front incline 22, the intermediate incline 24, and the rear incline 26, interact with the actuator 28. The actuator 28 may include a shaft 64 extending from a proximal end 66 to a distal end 68. The shaft 64 may include a first threaded portion 70, a second threaded portion 72, and a non-threaded portion 74. The second threaded portion 72 may be disposed between the first threaded portion 70 and the non-threaded portion 74. The threaded portions 70, 72 can have the same or different attributes including outer diameter, winding direction, thread shape, thread angle, lead, pitch, etc.

[0037] The front drive ramp 22 includes a through hole 58, and the front drive ramp 22 is disposed on the non-threaded portion 74 of the actuator 28. The intermediate ramp 24 includes a threaded hole 60, and the intermediate ramp 24 is disposed on the second threaded portion 72 of the actuator 28. The intermediate ramp 24 is threadably movable along the length of the second threaded portion 72 of the actuator 28. The rear ramp 26 is engaged with a nut 30, and the nut 30 is disposed along the first threaded portion 70 of the actuator 28 and is movable along the length of the first threaded portion 70. The intermediate drive ramp 24 and the rear drive ramp 26 are each movable along their respective threaded portions 72, 70 to move the upper end plate 12 and the lower end plate 14 and / or the upper carrier end plate 36 and the lower carrier end plate 40, thereby expanding the height of the implant 10. The threaded portions 70, 72 and the non-threaded portion 74 can have the same or different outer diameters. The threaded portions 70, 72 can have the same or different threading attributes or winding directions. The proximal end 66 of the actuator shaft 64 can include a first instrument retaining recess 76 having, for example, a slotted head. The instrument recess 76 may include one or more alternating fingers and slots, ribs, knurled grips, or other suitable engagement surfaces that are configured to interact with a driver instrument and thereby rotate the actuator shaft 28. The distal end 68 of the actuator shaft 28 may be threaded to receive a female-threaded lock nut 77 configured to secure the front ramp 22 to the actuator 28.

[0038] The actuating assembly 20 may include a rotatable nut or outer drive screw 30. The rotatable nut 30 may be configured to move the rearward ramp 26 independently of the intermediate ramp 24 and the forward ramp 22. The nut 30 may extend from a proximal end 78 to a distal end 80. The proximal end 78 may include a second instrument retaining mechanism such as a slotted head 82. The slotted head 82 may include fingers and slots or other suitable engagement surfaces configured to interact with a driver instrument and thereby rotate the nut 30. The distal end 80 may be threaded with a male thread to mate with a female-threaded rear locking nut 104. When only the nut 30 is rotated, the rearward ramp 26 may be translated forward such that the rear height increases. When the nut 30 remains stationary and only the actuator 28 is rotated, both the rearward ramp 26 and the intermediate ramp 24 may move rearward such that the forward height increases. When both the actuator 28 and the nut 30 are rotated simultaneously, the intermediate ramp 24 may move rearward, thereby translating the end plates 12, 14 in parallel. It will be understood that the movement of the drive ramps 22, 24, 26 and the resulting expansion may be operated by an actuator 28 and / or a nut 30 having any suitable configuration and mechanism.

[0039] The drive ramps 22, 24, 26 engage the upper and lower end plates 12, 14 and associated upper and lower carrier end plates 36, 40, thereby moving the upper and lower end plates 12, 14 and the upper and lower carrier end plates 36, 40 outwardly in height and / or forward bend.

[0040] As best seen in FIGS. 5 and 7, the upper end plate 12 includes an inner surface 52 configured to mate with the drive ramps 22, 26, and the upper carrier end plate 36 includes an inner surface 96 configured to mate with the drive ramp 24. The inner surfaces 52, 96 may include one or more inclined surfaces 54, 98. For example, the upper end plate 12 may include at least one first inclined surface 54 near the front portion 46 of the device 10, at least one second inclined surface 54 near the rear portion 48 of the device 10, and at least one third inclined surface 54 between the first inclined surface 54 and the second inclined surface 54. For example, the end plates 12, 14 may include a pair of first inclined surfaces 54, a pair of second inclined surfaces 54, and a pair of third inclined surfaces 54 oriented to engage the respective ramps 22, 24, 26.

[0041] The upper carrier end plate 36 may include at least one first inclined surface 98 facing the front portion 46 of the device 10 and at least one second inclined surface 98 facing the rear portion 48 of the device 10. The sidecar carrier 34 includes at least one inclined surface 100. For example, the outer surface of the sidecar carrier 34 may define a first upper inclined surface 100 and a second lower inclined surface facing toward the front portion 46 of the implant 10. The sidecar carrier 34 may include an inclined portion shape that mimics the shape of the rear ramp 26. In one embodiment, the first inclined surface 98 of the upper carrier end plate 36 facing the front portion 46 of the device 10 may be configured to slidably engage the ramp 86 of the intermediate drive ramp 24. The second inclined surface 98 facing the rear portion 48 of the device 10 may be configured to slidably engage the inclined portion 100 of the sidecar carrier 34. In this way, the upper end plate 12 and the upper carrier end plate 36 can act as one unit during expansion and thereby engage adjacent vertebral bodies.

[0042] The inclined surfaces 54, 98 may be angled continuous surfaces having a given inclination angle. It is considered that the inclinations of the inclined surfaces 54, 98 may be equal to each other or different from each other. The inclined surfaces 54, 98 may be substantially linear inclined surfaces or curved inclined surfaces. The inclined surfaces 54, 98 may include male sliding inclined surfaces or protruding inclined surfaces. The inclined surfaces 54, 98 may be spaced apart at equal distances such that the inclined surfaces are substantially parallel to each other. Although a specific arrangement of the inclined surfaces is shown, it is assumed that the number, location, and configuration of the inclined surfaces may be changed or selected by those skilled in the art.

[0043] The drive inclined portions 22, 24, 26 may include one or more inclined surfaces 84, 86, 88. The inclined surfaces 84, 86, 88 of the drive inclined portions 22, 24, 26 may be configured and dimensioned to engage the corresponding inclined surfaces 54, 98 of the upper and lower end plates 12, 14 and the upper and lower carrier end plates 36, 40, respectively. For example, the front inclined portion 22 may include one or more inclined surfaces 84, the middle inclined portion 24 may include one or more inclined surfaces 86, and the rear inclined portion 26 may include one or more inclined surfaces 88. For example, the front inclined portion 22 may include a first pair of upper inclined surfaces 84 and a second pair of lower inclined surfaces 84. The middle inclined portion 24 may include a first pair of upper inclined surfaces 86 and a second pair of lower inclined surfaces 86. The rear inclined portion 26 may include a first pair of upper inclined surfaces 88 and a second pair of lower inclined surfaces 88. The inclined surfaces 84, 86, 88 may be angled continuous surfaces having a given inclination angle. It is considered that the inclinations of the inclined surfaces 84, 86, 88 may be equal to each other or different from each other.

[0044] The inclined surfaces 84, 86, 88 may be substantially straight or curved inclined surfaces. The inclined surfaces 84, 86, 88 may each include a female sliding inclined surface or a concave inclined surface configured to receive the male inclined surfaces 54, 98 of the upper and lower end plates 12, 14 and the upper and lower carrier end plates 36, 40. For stability and reliability, a dovetail-type connection can be formed between the inclined surfaces, but other fitting and sliding engagements can also be used. It will be understood that the male and female inclined surfaces can be reversed or otherwise configured to provide a slidable fit between the inclined surfaces.

[0045] The front inclined surface 54 of the end plates 12, 14 may be configured to slidably engage the inclined surface 84 of the front drive ramp 22. The rear inclined surface 54 of the end plates 12, 14 may be configured to slidably engage the inclined surface 88 of the rear ramp 26. The intermediate inclined surface 54 of the end faces 12, 14 and / or the inclined surface 98 of the carrier end faces 36, 40 may be configured to slidably engage the inclined surface 86 of the intermediate ramp 24. When one or more of the drive ramps 22, 24, 26 move, one or more of the inclined surfaces 84, 86, 88 push against the corresponding one or more inclined surfaces 54, 98 of the upper and lower end plates 12, 14 and the upper and lower carrier end plates 36, 40. In this way, the individual drive ramps 22, 24, 26 control the expansion rate of the upper and lower end plates 12, 14 and the upper and lower carrier end plates 36, 40. The upper and lower end plates 12, 14 and the upper and lower carrier end plates 36, 40 are pushed outwardly into one of the expanded configurations.

[0046] To further highlight FIGS. 11 - 14, the implant 10 has a spike deployment assembly 32 configured to deploy upper and lower spike assemblies 16, 18. The upper spike assembly 16 includes upper spikes 38 hinge - connected to an upper carrier end - plate 36, and the lower spike assembly 18 includes lower spikes 42 hinge - connected to a lower carrier end - plate 40. The spike deployment assembly 32 may include a side - car carrier 34 connected to the upper and lower carrier end - plates 36, 40. The presence of the retention spikes 38, 42 prevents expulsion to a greater extent than a spacer having no expulsion - resistance feature. By integrating the retention spikes 38, 42 inside the implant 10, the number of steps to deploy the spikes 38, 42 is reduced, and it becomes possible to deploy them using the same inserter used to place the spacer 10.

[0047] To further highlight FIGS. 5 and 6, the spikes 38, 42 are configured to be deployed through the main end - plates 12, 14. The main end - plates 12, 14 include elongated side channels 110 that receive and guide the spikes 38, 42. Each end - plate 12, 14 defines a channel 110 that passes through an extension 90 of the end - plate 12, 14 along the main longitudinal axis of the implant 10. The channels 110 are sized and dimensioned to receive, guide, and deploy the respective spikes 38, 42. The extension 90 further defines a passage 112 for receiving the tasks 114 of the carrier end - plates 36, 40.

[0048] To explain FIG. 7 in more detail, each carrier end plate 36, 40 includes an elongated tab 114 that extends toward the front portion 46 of the implant 10. The tab 114 may have a polygonal cross-section, for example, a generally square or rectangular shape corresponding to the shape and dimensions of the passageway 112. The tab 114 may be integral with the carrier end plates 36, 40 or may be connected thereto in any suitable manner. The upper and lower carrier end plates 34, 40 are each constrained to the upper and lower main end plates 12, 14 via the tab 114 that extends from the leading edge of the carrier end plates 36, 40 and is inserted into the respective passageway 112 within the main end plates 12, 14. The tab 114 allows for translation of the carrier end plates 36, 40 relative to the main end plates 12, 14 along the main longitudinal axis of the device 10, but limits all other translations and rotations.

[0049] As shown in FIGS. 9 and 10, each spike 38, 42 may be connected to the respective carrier end plate 36, 40 by a pin 116. The pin 116 may be receivable through an opening 118 within the carrier end plate 36, 40 to provide a pivotable connection between the end plates 36, 40 and the spikes 38, 42. The anchor or spike 38, 42 may extend from a proximal end 120 coupled to the end plate 36, 40 to a distal end or free end 122. The free end 122 of the spikes 38, 42 can have a pointed or sharpened end 122 configured to penetrate bone. The spikes 38, 42 may be curved or contoured along their body such that the spikes 38, 42 move further outward as they are deployed. Although curved spikes are illustrated, the spikes 38, 42 can include any suitable anchor, shim, or fastener configured to resist expulsion of the device 10.

[0050] As carrier end plates 36, 40 move forward toward main end plates 12, 14, task 114 moves through passage 112 and spikes 38, 42 move through notch channels 110 in main end plates 12, 14. As carrier end plates 36, 40 move forward, spikes 38, 42 reach the bottom on the respective floors of channels 110 and rotate spikes 38, 42 about the axes of respective pins 116 that connect spikes 38, 42 to carrier end plates 36, 40. As best seen in FIG. 10, spikes 38, 42 emerge from the top and bottom surfaces of main end plates 12, 14, thereby deploying spikes 38, 42 outwardly into adjacent vertebral bodies.

[0051] Although pins 116 are illustrated, it will be understood that the attachment and capture of spikes 38, 42 can be accomplished in several ways. In the embodiments presented herein, spikes 38, 42 are captured and pinned by walls within carrier end plates 36, 40. This configuration may also be accomplished by incorporating pin-like posts remote from the sides of the spikes themselves, which may reduce the need for additional components. Attachment may also be accomplished, for example, by a threaded ball and socket interface that allows a threaded ball on the end of the spike to be screwed into a female threaded spherical socket.

[0052] To describe FIG. 8 in more detail, the rearward inclined portion 26 may include a double - tail 130 and a retaining tab 132 to direct and lock the movement of the side - car carrier 34. The rearward inclined portion 26 may include a pair of arms 134 around the bore 62. The inner surface of each arm 134 may define, for example, a threaded portion configured to engage with an instrument. One arm 134 of the rearward inclined portion 26 can define a double - tail slot 130 along the outer surface of the inclined portion 26. The carrier 34 has a corresponding double - tail that mates with the double - tail slot 130 of the rearward inclined portion 26, allowing the carrier 34 to translate relative to the rearward inclined portion 26 along the major longitudinal axis of the device 10 while restricting all other translations or rotations. The double - tail 130 can follow a path of decreasing height toward the rear of the rearward inclined portion 26 so that the carrier 34 is captured and cannot fully retract from the inclined portion 26.

[0053] The retaining tab 132 may function as an automatic lock to prevent the retraction of the spikes 38, 42 after deployment. The retaining tab 132 may be formed from a relief cut that defines a polygonal tab such as a square or rectangular tab. The tab 132 may be configured to project outwardly, for example, toward the front end 46 of the implant 10. In this way, when the side - car carrier 34 passes over the tab 132, the tab 132 rises outwardly, preventing the side - car carrier 34 from returning toward the rear end 48 of the implant 10. As best seen in FIG. 11, when the spike deployment assembly 32 is fully retracted, the side - car carrier 34 blocks the retaining tab 132 on the rearward inclined portion 26. As best seen in FIG. 12, when the spike deployment assembly 32 is fully advanced forward, the side - car carrier 34 releases the retaining tab 132 of the rearward inclined portion 26, thereby preventing the spike deployment assembly 32 from translating rearward and keeping the spikes 38, 42 in the deployed state. The presence of the automatic - lock retaining tab 132 reduces the need for an additional locking step to hold the spikes 38, 42.

[0054] In an exemplary embodiment, the entire carrier assembly 32 is incorporated within the spacer body. In this way, separate spikes or other anti-repulsion elements are not required to fix the device 10. Although the double tails 130 and the retaining tabs 132 are illustrated herein, it will be understood that locking the spikes 38 into the deployed configuration can be achieved in several ways. For example, another way to achieve the same function may include positioning the sidecar carrier 34 or the carrier end plate assembly 32 on the inserter. The inserter then pushes the automatic locking mechanism forward and is configured to directly hold the spikes 38, 42.

[0055] To further highlight FIGS. 11-14, a method of installing and assembling the fixation device 10 according to one embodiment is shown. Prior to insertion of the fixation device 10, the intervertebral space is prepared. An intervertebral discectomy may include osteotomy of the posterior elements and the ligamentum flavum and creating a wide passage to the underlying dural sac and the disc space below. A osteotome may be used to remove the posterior spinous process and the disc. In one method, a discectomy is performed and the disc may be removed in its entirety or in part. The endplates of the adjacent vertebral bodies may be scratched to create exposed end faces to facilitate bone growth across the intervertebral space. The anterior longitudinal ligament (ALL) may be released via a spreader or blunt dissection.

[0056] One or more endoscope tubes may be inserted into the disc space. As best seen in FIG. 11, one or more expandable fixation devices 10 may be introduced into the intervertebral space in a folded configuration and installed in an appropriate position within the disc space. The expandable implant 10 may be installed via a posterior lumbar interbody fusion (PLIF) trajectory.

[0057] After the fixation device 10 has been inserted into the appropriate position within the intervertebral space, the retention spikes 38, 42 can be deployed as shown in FIG. 12 by translating the sidecar carrier 34 towards the front end 46 of the implant 10. As the sidecar carrier 34 translates forward, the upper and lower carrier end plates 36, 40 are guided by the task 114 to translate forward. The spikes 38, 42 pivotally connected to the carrier end plates 36, 40 translate forward and pivot outwardly to an expanded configuration.

[0058] The fixation device 10 may be expanded to an extended height either before or after deploying the spikes 38, 42. As shown in FIG. 13, the end plates 12, 14, 36, 40 may be expanded in parallel. As shown in FIG. 14, the end plates 12, 14, 36, 40 may be expanded in an anteriorly curved configuration. The expandable spacer 10 provides independently adjustable height and anterior curve, which allows the user to fine-tune the final profile to match the patient's unique anatomical structure.

[0059] The rod may be reduced in diameter to a screw placed prior to osteotomy, and the screw is compressed. As the screws are brought closer together, the vertebral body can pivot about a fulcrum formed by the intervertebral spacer, increasing the segmental lordosis and providing the desired correction.

[0060] Referring now to FIGS. 15 - 18, one embodiment of an expandable fixation device 10 is shown having one or more electrical components 136 for operating the implant 10 and / or communicating with a robotic system 138. Robotic assistance and / or navigation assistance can be used to pre-plan and improve the accuracy / efficiency of the placement and fixation of the intervertebral implant. The orientation and position of the implant 10 at the final implantation position can be optimized by preoperative and intraoperative scans utilizing the robotic system and / or navigation system. Robotic and / or navigation guidance may be used to accurately orient and align the implant for the desired expansion and deployment of the integrated spikes 16, 18.

[0061] Robotics can use images taken prior to placing the intervertebral implant for initial alignment. This procedure can relay the real-time position of instruments and devices, depending on the direct visualization of movement markers, which is superimposed on the first imaging. As a result, when the intervertebral is placed, the expansion and resulting anatomical position changes may not be reflected on the navigation display. Therefore, there is a need for an implant that can relay its position and orientation to a computer in a way that does not require direct visualization. Additionally, or alternatively, there is a need for a device that is autonomously adjustable, using a number of independently adjustable features and small working passages, without the need for direct mechanical interaction with the implant 10.

[0062] According to one embodiment, the implant 10 is configured to communicate the position and orientation of the implant 10 to the robot 138 before, during, and after the implant 10 expands. FIG. 18 shows an example of a system flowchart showing the implant 10 having embedded electrical components 136, an inserter 150 having an electromagnet 152 and a wireless charger 154 configured to install the implant 10, and a robot / navigation system 138 having a wireless receiver 156 and a wireless transmitter 158 configured to transmit and receive information between the implant 10, drive screws 28, 30, a holding spike carrier 34 for deploying spikes 38, 42, and drive ramps 22, 24 for adjusting height and lordosis, and the mechanical components of the implant 10. It will be understood that the electrical components 136 within the implant 10 are electrically coupled or connected to each other in a suitable manner to transfer energy, power, and / or information between the components.

[0063] The robot and / or navigation system 138 may include a surgical robot system having an end effector coupled to a robotic arm, a control device (e.g., a computer having a processor and a memory coupled to the processor) for controlling the robotic arm and the end effector, and a display for receiving user input and displaying information to the user. The end effector may be configured to hold and / or guide the inserter 150 during the surgery. The robot / navigation system 138 includes a wireless receiver 156 for receiving information such as the force and position information of the implant from the implant 10, and a wireless transmitter 158 for transmitting user input to the implant 10. Further examples of surgical robots and / or navigation systems can be found, for example, in U.S. Patent No. 10,675,094, U.S. Patent No. 9,782,229, and U.S. Patent Application Publication No. 2017 / 0239007, which are hereby incorporated by reference in their entirety for all purposes.

[0064] According to one embodiment, the spacer 10 can relay its position to the robot and / or navigation system 138, which overcomes a significant obstacle related to preoperative imaging when alignment is lost after placement of the spacer 10. In addition, the orientation, position, expansion, and / or deployment of the spacer can be tracked in real time to better inform the procedure to be navigated after spacer placement.

[0065] The implant 10 can include electrical components 136 such as sensors 140, 146, a memory / storage / computing device 142, actuators 144, 162, a power source 164, and a wireless communication system 160 embedded in various components throughout the spacer 10. The implant 10 may include an outer housing 135 configured to receive, for example, a computing unit 142, a motor for operating the drive screws 28, 30, a wireless communication unit 160, a linear servo 162 for operating the sidecar carrier 34, and a wireless charger 164 for providing power to the device 10.

[0066] The electronic component 136 may be involved in up to three main operations. (1) Measurement of the force distribution across the implant 10, (2) subsequent adjustment of the height and anterior curvature of the implant, and / or (3) monitoring and communication of the position and loading of the implant. The end effector of the robot 138 and / or the user can hold the inserter 150 for positioning the implant 10. The wireless charger 154 within the inserter 150 may be used to wirelessly provide power to the implant 10, and the electromagnet 152 may be used to assist in position sensing by the implant 10.

[0067] As best seen in FIGS. 16 - 17, one or more force sensors 140 may be included in or on the main end plates 12, 14. For example, the force sensors 140 may be housed in the front and rear portions of both the upper main end plate 12 and the lower main end plate 14. The force sensors 140 may be involved in load distribution measurement.

[0068] The computing unit 142 may be included within the implant 10, for example, within the posterior incline 26. The computing unit 142 may include a processor or processing unit having memory, storage, and / or software. The computing unit 142 may be configured to monitor relative forces over time to determine the load distribution. The computing unit 142 supplies this load distribution information via an algorithm to determine the appropriate height / anterior curvature changes and rates of change.

[0069] Once a determination is made, the computing unit 142 notifies one or more electric motors 144 to adjust the height of the implant 10. For example, a pair of DC motors 144 may be provided within the housing 135 behind the two drive screws 28, 30. The computing unit 142 may provide information including the drive amount and duration to the motor 144. The motors 144 are configured to automatically drive or rotate the two screws 28, 30 to provide the desired amount and type of expansion to the upper and lower end plates 12, 14.

[0070] The implant 10 may include one or more Hall effect sensors 146. For example, the Hall effect sensors 146 may be housed on or within each of the front ramp 22 and the middle ramp 24. A separate electromagnet 152 may be provided, for example, on the insertion instrument 150. When the electromagnet 152 generates a small magnetic field, the Hall effect sensor 146 detects the relative positions of the front ramp 22 and the middle ramp 24 from the rear ramp 26 that is rigidly constrained to the inserter 150. For any given relative position of the front ramp 22, the middle ramp 24, and the rear ramp 26, there is a single known position and orientation of the main end plates 12, 14. In this way, the relative positions of the ramps 22, 24 read from the Hall effect sensor 146 provide sufficient information to project the real-time implant position state. This information can be projected onto the display of the robot / navigation system 138 after the sensor information has been processed by the computing unit 142. The information can be transmitted wirelessly via a wireless communication unit 160, which is also identified as a wireless transmitter and a wireless receiver on the system flowchart. The wireless communication unit 160 may be housed, for example, within the body of the rear ramp 26.

[0071] When the user confirms the final placement of the implant 10, a command is issued by the user and received by the wireless communication unit 160 to initiate deployment. The computing unit 142 provides information including drive start and duration to the linear servo motor 162. The linear servo motor 162 may be housed behind the sidecar carrier 34 and pushes the carrier 34 forward, thereby deploying the holding spikes 38, 42.

[0072] Throughout the operation, the inserter 150 can include at its end a wireless charger 154 that interfaces with a receiving charger 164. The receiving charger 164 may be housed, for example, within the rearwardly inclined portion 26 and provides power for the autonomous operation of the implant 10. In this way, the spacer 10 can drive itself autonomously, thereby reducing the need for a plurality of drivers for driving the front and rear heights as well as anchor deployment. This simplifies the operation workflow and improves the efficiency of spacer placement. Also, by reducing the number of instruments, the required working passageways and tissue disruption are reduced, and the patient's recovery time can be improved.

[0073] Referring now to FIGS. 19-27, a hybrid implant 200 according to another embodiment is shown. The expandable implant 200 includes integrated deployable retention spikes 16, 18 with some modifications to the spike retention mechanism, channel shape, spike actuation path, and / or order of implant operation, similar to the implant 10.

[0074] The implant 200 includes an expansion platform and a sidecar spike deployment assembly. As best seen in FIG. 19, the expansion platform may include upper and lower main end plates 12, 14, two concentric drive screws 28, 30, two translational inclined portion components 22, 24, two lock nuts 77, 104, and three PEEK washers 102, 106, similar to the implant 10. A third rearwardly inclined portion component 26 can function as a connection between the expansion platform and the spike deployment platform.

[0075] The spike deployment platform includes an inclined sidecar carrier 34, and the inclined portion 100 of the inclined sidecar carrier 34 is connected to two carrier end plates 36, 40 that each hold two respective spikes 38, 42. The spikes 38, 42 and the carrier end plates 36, 40 translate inside and outside of channels 210, 212 within two main upper and main lower end plates 12, 14, and the two main upper and main lower end plates 12, 14 are connected to the expansion platform using an inclined ramp 54. The upper and bottom carrier end plates 34, 40 are respectively constrained to the upper and bottom main end plates 12, 14 via tasks or pushers 214 that extend from the leading edges of the carrier end plates 36, 40 and are inserted into respective passages 212 within the main end plates 12, 14. The pusher 214 allows translation of the carrier end plates 36, 40 relative to the main end plates 12, 14 along the main longitudinal axis of the device 200, but limits all other translation and rotation.

[0076] Movement of the expansion platform allows for height expansion, and the spike deployment platform allows for deployment of the spikes 16, 18. As best seen in FIG. 20, the expandable implant 200 may be inserted in a folded and collapsed position and then expanded in height and / or lordosis. The carrier end plates 36, 40 may engage the main end plates 12, 14 and follow their movement through height and lordosis expansion. As best seen in FIG. 21, the anchors or spikes 38, 42 may be deployed into adjacent vertebral bodies to provide stability and prevent expulsion from the intervertebral disc space. In this embodiment, the user has the ability to deploy the spikes 38, 42 either before or after the implant 200 is expanded in height / lordosis, thereby providing more flexibility in the order of implant operation and the workflow of the procedure.

[0077] In the embodiment previously described for implant 10, retention spikes 38, 42 are pinned to carrier end plates 36, 40. The pinning causes spikes 38, 42 to pivot about the axis of pin 116 as they move through their deployment operative path. This can result in a front windshield wiper operative path that can pull the implant itself forward when spikes 38, 42 are deployed, and / or spikes 38, 42 can cut arcuate recesses within the vertebral endplate. By removing the pins as the retention and deployment mechanism for spikes 38, 42, spikes 38, 42 are enabled to rotate about their own centers of curvature rather than about the pins. This keeps the front windshield wiper from moving during deployment, keeps the movement of the spikes tangential to their own shape, optimizes retention within bone, and reduces the likelihood of void formation during deployment.

[0078] In this embodiment with respect to implant 200, the pin(s) may be replaced with an alternative movable joint. For example, as shown in FIGS. 22 - 24, the joint can include a pivot joint, a hinge joint, a saddle joint, a ball and socket joint, or other suitable joint for rotating, pivoting, and / or extending respective spikes 38, 42. The embodiment of FIGS. 22 - 24 is illustrated and described with respect to upper carrier end plate 36 and upper spike 38, but it will be understood that this description applies equally to lower carrier end plate 40 and lower spike 42.

[0079] In one embodiment shown in FIGS. 22A - 22B, the joint may include a pivot joint with a convex base 202 on the proximal ends 120 of spikes 38, 42 that is captured within a corresponding pocket 218 on the distal end 216 of the carrier end - plate pusher 214. In this way, spikes 38, 42 are retained within the carrier end - plate pusher 214 via the interface between the convex base 202 and the pocket 218. The pocket 218 allows the convex base 202 to move vertically along the vertical axis, and spikes 38, 42 are pushed forward, rotated, and translated to their deployed position / orientation. The pocket 218 on the pusher 214 may be under - cut such that the under - cut pulls on the front surface of the convex base 202 and can retract spikes 38, 42 after deployment.

[0080] The anchor or spikes 38, 42 may extend from a proximal end 120 engaged with the carrier end - plates 36, 40 to a distal end or free end 122. The proximal ends 120 of spikes 38, 42 may include, for example, a convex base 202 having generally a convex outer shape. The convex outer shape of the base 202 is rounded but may be non - spherical. The bottom surface of spikes 38, 42 may define an under - cut or slot 204, whereby the convex base 202 projects beyond the ends of spikes 38, 42 or forms a downward hook. The slot 204 may have a smooth rounded surface. The free ends 122 of spikes 38, 42 on the opposite side may have pointed or sharpened ends 122 configured to penetrate bone. The upper surface of spikes 38, 42 may define one or more grooves or scoops 206 along their longitudinal length. For example, a pair of scoops 206 may be bifurcated by a rib extending centrally between them. Spikes 38, 42 may be curved or contoured along their body with a given degree of curvature such that they move along a curved path when spikes 38, 42 are deployed.

[0081] The carrier end plates 36, 40 include an upper surface 94 for engaging adjacent vertebrae (e.g., toothed) and a lower surface 96 having an inclined portion 98 that slidably engages with the intermediate inclined portion 24 and / or one or more corresponding inclined portions 86, 100 on the sidecar carrier 34, thereby providing an extension of the height of the carrier end plates 36, 40 in cooperation with the upper and lower main end plates 12, 14. Similar to the task 114, each carrier end plate 36, 40 includes an extension, rod, or pusher 214 that extends towards the front portion 46 of the implant 10. The pusher 214 may have a larger cross-section than the task 114 and may have any suitable cross-section, for example, a cylindrical or polygonal shape corresponding to the shape and dimensions of the linear passage 212 passing through the main end plates 12, 14. The pusher 214 may extend longitudinally from the front portion of the carrier end plates 36, 40, may be integral with the carrier end plates 36, 40, or may be connected thereto in a suitable manner.

[0082] As best seen in FIG. 22B, the pusher 214 terminates distally at a tip or free end 216. The upper portion of the pusher 214 defines a pocket 218 configured to receive the corresponding convex bases 202 of the spikes 38, 42. The pocket 218 may be undercut such that the tip 216 defines an overhang or upward hook at the end of the pusher 214. In this way, the upward hook of the tip 216 can be received within the slots 204 of the spikes 38, 42, and the downward hook of the base 202 can be received within the pocket 218 of the pusher 214. The pocket 218 is shaped such that the convex base 202 can move freely up and down along the vertical axis but remains held therein. Thereby, the spikes 38, 42 can rotate about an axis that coincides with their own radius of curvature, thereby eliminating the movement of the front windshield wiper.

[0083] Referring now to FIGS. 23A - 23B, another embodiment of a ball socket joint connecting spikes 38, 42 to pusher 214 is shown. In this embodiment, the convex base 202 is replaced by a ball 222, and the pocket 218 in pusher 214 is replaced by a socket 224 sized and configured to receive ball 222. Ball 222 may be a complete sphere that can be received within socket 224. The sphere 222 may have its upper portion partially cut away to minimize interference during rotation. Ball 222 may be separated from the body of spikes 38, 42 having a neck 226 with a reduced diameter relative to ball 222. The ball and socket combination allows spikes 38, 42 to pivot around the joint, thereby enabling spikes 38, 42 to pivot and extend outwardly during deployment.

[0084] Referring now to FIGS. 24A - 24B, another embodiment of a partial ball and socket joint connecting spikes 38, 42 to pusher 214 is shown. Similar to the embodiment shown in FIGS. 23A - 23B, the proximal ends 120 of spikes 38, 42 include a ball 222 that can be received within socket 224 at the distal end 216 of pusher 214. In this embodiment, ball 222 may define a partial sphere and may include one or more ribs configured to hold ball 222 and / or guide the movement of spikes 38, 42. Neck 226 may define a flat portion connecting the truncated upper surface of ball 222 to the body of spikes 38, 42. The partial ball and socket combination allows spikes 38, 42 to pivot around the joint, thereby enabling spikes 38, 42 to pivot and extend outwardly during deployment.

[0085] Referring now to FIGS. 25A - 25B, the sidecar assembly is movable via a slidable interface with the rear drive ramp 26. Similar to the implant 10, the rear ramp 26 can include one or more double tails 230 and retaining tabs 232 to direct and lock the movement of the sidecar carrier 34. In this embodiment, a single double tail 130 has been replaced with a pair of parallel double tails 230 disposed on either side of the retaining tab 232. As best seen in FIG. 25A, the slidable double tail 230 can include a recess or slot within the body of the rear ramp 26 and an extension or peg extending from the sidecar carrier 34. The peg can be flared or enlarged at the free end to resist separation of the components. This configuration may be reversed, some slidable double tails may be used, or another interface may be used to allow for slidable engagement between the sidecar carrier 34 and the rear ramp 26, it will be understood. The parallel double tail slots 230 on the side of the rear ramp 26 engage corresponding double tails on the sidecar carrier 34, allowing the sidecar carrier 34 to slide forward and backward. The carrier end plates 36, 40 have inclined ramps 98 which engage receiving ramps 100 on the sidecar carrier 34, whereby the carrier end plates 36, 40 can be pulled forward and backward with the sidecar carrier 34 and also move up and down along the ramps 98, 100. The rear ramp 26 and / or the sidecar carrier 34 can include one or more holder recesses 234 configured to connect with an inserter or other instrument (not shown).

[0086] Referring more particularly to FIGS. 26 - 28, the upper and lower end plates 12, 14 each define a channel 210 for receiving spikes 38, 42 and a channel 212 for receiving a pusher 214. In implant 10, there were two separate channels 110, 112 in each end plate 12, 14: one for receiving guide task 114 from carrier end plates 36, 40 and one for guiding retention spikes 38, 42 through their deployment path. In implant 200, these channels 210, 212 are aligned with each other. This allows for all of the pusher 214, retention spikes 38, 42, and both of the associated channels 210, 212 to be enlarged, reducing the need for lateral nesting of these features. These changes can serve to improve the manufacturability and mechanical strength of implant 200.

[0087] As best seen in FIG. 26, spike channel 210 is a curved channel configured to hold and guide the deployment of spikes 38, 42, and pusher channel 212 is a straight channel configured to receive the distal end 216 of pusher 214 when spikes 38, 42 are deployed. The straight channel 212 may be a blind channel extending generally along the major longitudinal axis of implant 200 between the front and rear portions of end plates 12, 14. The curved channel 210 may arc outwardly towards the outer surface 50 of each end plate 12, 14. The curved channel 210 for spikes 38, 42 and the straight channel 212 for pusher 214 overlap such that these channels 210, 212 intersect each other. By arranging the curved channel 210 and the straight channel 212 so that they overlap, both channels 210, 212 can be made larger within a given envelope of end plates 12, 14, thereby increasing the size and strength of the members 38, 42, 214 passing through them.

[0088] As best seen in FIG. 27, in the retracted position, spikes 38, 42 are held inside the curved channels 210 that pass through end plates 12, 14. The pusher 214 holds the spikes 38, 42 and guides each carrier end plate 36, 40 in and out of the straight channels 212 on their associated main end plates 12, 14. When the sidecar carrier 34 and the carrier end plate assembly are pushed forward, each spike 38, 42 is deployed through its respective curved channel 210 in the main end plates 12, 14. The pusher 214 moves forward and follows the straight channels 212. As best seen in FIG. 28, in the deployed position, the spikes 38, 42 extend outwardly from the main end plates 12, 14 following the curved channels 210. The spikes 38, 42 emerge from the top and bottom surfaces of the main end plates 12, 14, thereby deploying the spikes 38, 42 outwardly into the adjacent vertebral bodies.

[0089] Furthermore, it should be understood that various changes in the details, materials, and arrangements of the parts described and illustrated to explain the nature of the present invention may be made by those skilled in the art without departing from the scope of the invention as set forth in the claims. It will be understood by those skilled in the art that the above embodiments are non-limiting. It will also be understood that one or more features of one embodiment may be partially or fully incorporated into one or more other embodiments described herein.

Claims

1. An upper main end plate and a lower main end plate configured to engage adjacent vertebrae, each of the upper main end plate and the lower main end plate including an elongated side channel for receiving and guiding a spike respectively, each of the side channels including a curved channel and a straight channel, the upper main end plate and the lower main end plate, and An actuator assembly configured to cause an expansion of the height of the upper and lower main end plates, and A sidecar assembly including a sidecar carrier provided on a side of the actuator assembly, an upper carrier end plate, and a lower carrier end plate, the upper carrier end plate and the lower carrier end plate being configured to hold two of the spikes, the sidecar assembly, comprising: an expandable implant, wherein The spike is A retracted position in which the spike is received within the curved channel and the straight channel, and It is movable between a deployed position in which the spike is deployed into the adjacent vertebrae to provide stability and prevent discharge from the intervertebral disc space, The sidecar assembly includes a pusher engaged with the spike, the spike is positionable through the curved channel, the pusher is receivable within the straight channel, and a forward translation of the sidecar carrier deploys the spike.

2. The upper main end plate and the upper carrier end plate are nested together to form an entire upper end plate of the implant, The lower main end plate and the lower carrier end plate are nested together to form an entire lower end plate of the implant, the expandable implant according to claim 1.

3. The pusher is disposed between the spike and the upper carrier end plate and the lower carrier end plate, the expandable implant according to claim 1.

4. The curved channel and the straight channel define one channel in communication with each other such that a corresponding spike is slidable along the one channel, the expandable implant according to claim 1.

5. The curved channel and the straight channel overlap such that the curved channel intersects the straight channel, the expandable implant according to claim 1.

6. The expandable implant according to claim 1, wherein the linear channel is a blind channel extending along the longitudinal axis of the implant.

7. The expandable implant according to claim 1, wherein the curved channel draws an arc outwardly toward the outer surface of the upper or lower main end plate.

8. In the retracted position, the spike is held inside the curved channel, and when the sidecar carrier translates forward, the spike moves through the curved channel, extends from the curved channel, and the pusher follows the linear channel. The expandable implant according to claim 1.

9. The expandable implant according to claim 1, wherein the spike extends from a proximal end to a free end, and a movable joint connects the proximal end of the spike to the distal end of the pusher.

10. The expandable implant according to claim 9, wherein the proximal end of the spike includes a convex base that can be received in a corresponding pocket in the pusher, and the pocket enables the convex base to move along a vertical axis to deploy the spike. The movable joint is a pivotable joint.

11. The expandable implant according to claim 9, wherein the movable joint is a ball-and-socket joint.

12. The expandable implant according to any one of claims 1 to 11, wherein the pusher is rotatably coupled to the spike such that the spike is rotatable relative to the pusher.

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