US-12616583-B2 - Expandable fusion device with independent expansion systems

US12616583B2US 12616583 B2US12616583 B2US 12616583B2US-12616583-B2

Abstract

Expandable spinal fusion devices, systems, and methods of using them are provided, and they can be inserted in a subject in a collapsed state through a small surgical corridor, and the expand cephalocaudal only, transverse only, or in both directions, in which direction of expansion can also be obtained independently, if desired, after the insertion. These inventions are valuable in reducing risk and surgical complexity, allowing for an on-the-fly selection of a desirable width footprint, a desired control of height expansion through a gradual cephalocaudal expansion, and a desired control of the alignment of the adjacent vertebral bodies. Devices, systems, and methods are also offered to provide a desired control of the contact area desired between the device and the upper and lower vertebral endplates achieved, for example, using an interdigitated endplate system.

Inventors

Eugene Shoshtaev

Assignees

INTEGRITY IMPLANTS, INC.

Dates

Publication Date: 20260505
Application Date: 20230627

Claims (20)

1 . An expandable fusion device, comprising: a first endplate, a second endplate, a third endplate, and a fourth endplate, two endplates of which form an upper endplate assembly, and the remaining two of which form a lower endplate assembly; a cephalocaudal expansion assembly configured to cause a cephalocaudal expansion between the upper endplate assembly and the lower endplate assembly; a transverse expansion assembly configured to cause a transverse expansion within the upper endplate assembly and the lower endplate assembly; and an expansion lock, wherein: one of the cephalocaudal expansion assembly and the transverse expansion assembly is a drive system and the other of the cephalocaudal expansion assembly and the transverse expansion assembly is a spacer system, the drive system having an actuator including a drive feature and a longitudinal axis, a wedge assembly coupled to the actuator, and a ramp assembly slidably coupled with the wedge assembly, wherein each of the first endplate, second endplate, third endplate, and fourth endplate is slidably coupled with the ramp assembly; and the spacer system having at least a first spacer configured for insertion between a first pair of adjacent endplates selected from the group consisting of the first endplate, the second endplate, the third endplate, and the fourth endplate; the first spacer is selected for a desired amount of expansion; and the expansion using the drive system operates independent of the expansion using the spacer system.
2 . The expandable fusion device of claim 1 , wherein: the spacer system includes a second spacer configured for insertion between the remaining pair of adjacent endplates, the remaining pair selected from the group consisting of the first endplate, the second endplate, the third endplate, and the fourth endplate; wherein, the second spacer is selected for a desired amount of expansion; the upper endplate assembly includes the first endplate and the second endplate; the lower endplate assembly includes the third endplate and the fourth endplate; the cephalocaudal expansion assembly includes the drive system wherein the upper endplate assembly is slidably coupled with the ramp assembly the lower endplate assembly is slidably coupled with the ramp assembly, and the cephalocaudal expansion assembly is configured to cause a cephalocaudal expansion between the upper endplate assembly and the lower endplate assembly upon an activation of the actuator; and the transverse expansion assembly includes the spacer system for the transverse expansion, the first spacer is configured for insertion between the first endplate and the second endplate, and the second spacer is configured for insertion between the third endplate and the fourth endplate.
3 . The expandable fusion device of claim 1 , wherein the first endplate, the second endplate, the third endplate, and the fourth endplate are each a rigid beam having a longitudinal axis.
4 . The expandable fusion device of claim 1 , wherein the actuator has a distal end and a proximal end, wherein at least a portion of the distal end comprises a first thread feature, wherein at least a portion of the proximal end comprises a second thread feature, and wherein the proximal end comprises the drive feature, and the drive feature is configured to attach to a corresponding drive element of a driving instrument.
5 . The expandable fusion device of claim 1 , wherein the wedge assembly comprises a distal wedge and a proximal wedge.
6 . The expandable fusion device of claim 1 , wherein the ramp assembly comprises a first distal ramp, a second distal ramp, a first proximal ramp, and a second proximal ramp.
7 . The expandable fusion device of claim 1 , wherein at least one of the second endplate and the fourth endplate is larger than at least one of the first endplate and the third endplate.
8 . The expandable fusion device of claim 1 , wherein the expansion lock is a friction lock configured to lock with contact between the wedge assembly and the ramp assembly.
9 . The expandable fusion device of claim 1 , wherein the expansion lock includes a snap lock between the first spacer and the first pair of adjacent endplates, the second spacer and the remaining pair of adjacent endplates, or both.
10 . The expandable fusion device of claim 1 , wherein the expansion lock is a means for locking into place the expansion of first pair of adjacent endplates, the remaining pair of adjacent endplates, or both.
11 . A method of fusing an intervertebral space of a subject, comprising: inserting the device of claim 1 into an intervertebral space of the subject with an inserter tool; and performing cephalocaudal expansion and transverse expansion of the device by (i) actuating the drive system, and (ii) inserting the spacer system into the device, the actuating and inserting performed independently and in separate steps; wherein the performing of the expansion using the drive system is independent of the expansion using the spacer system.
12 . The method of claim 11 , the method further comprising: attaching an inserter tool to the device for the inserting; and driving the actuator with the drive element of a driving instrument, the drive element configured for engaging with the drive feature of the actuator.
13 . The method of claim 11 , wherein the actuator has a distal end and a proximal end, at least a portion of the distal end comprises a first thread feature, at least a portion of the proximal end comprises a second thread feature, the proximal end comprises the drive feature, and the drive feature is configured to attach to a corresponding drive element of a driving instrument, the method further comprising: attaching an inserter tool to the device for the inserting; and driving the actuator with the drive element of a driving instrument, the drive element configured for engaging with the drive feature of the actuator and rotating the actuator with the driving instrument.
14 . A method of fusing an intervertebral space of a subject, comprising: inserting the device of claim 2 into an intervertebral space of the subject; performing the transverse expansion using the spacer system, the performing including inserting the first spacer and the second spacer in the device; and performing cephalocaudal expansion using the drive system, the performing including actuating the drive system in the device, wherein the actuating and inserting are performed independently and in separate steps.
15 . The method of claim 14 , the method further comprising: attaching an inserter tool to the device for the inserting; and driving the actuator with the drive element of a driving instrument, the drive element configured for engaging with the drive feature of the actuator.
16 . The method of claim 14 , wherein the actuator has a distal end and a proximal end, at least a portion of the distal end comprises a first thread feature, at least a portion of the proximal end comprises a second thread feature, the proximal end comprises the drive feature, and the drive feature is configured to attach to a corresponding drive element of a driving instrument, the method further comprising: attaching an inserter tool to the device for the inserting; and driving the actuator with the drive element of a driving instrument, the drive element configured for engaging with the drive feature of the actuator and rotating the actuator with the driving instrument.
17 . An expandable fusion device that is expandable in length, the device comprising: a first expandable device coupled to a second expandable device; a first actuator for expanding the first expandable device and the second expandable device; and a second actuator configured for coupling the first expandable device to the second expandable device.
18 . The expandable fusion device of claim 17 , wherein the first actuator is part of a drive system having: a first wedge assembly for the first expandable device coupled to the first actuator and a first ramp assembly slidably coupled with the first wedge assembly; and a second wedge assembly for the second expandable device coupled to the first actuator and a second ramp assembly slidably coupled with the second wedge assembly, wherein each of the first expandable device and the second expandable device include a first endplate, a second endplate, a third endplate, and a fourth endplate, each endplate of which is slidably coupled with the ramp assembly.
19 . A laterally expandable fusion device, comprising; an upper endplate assembly having a first endplate with a first plurality of protrusions and a second endplate with a second plurality of protrusions; and a lower endplate assembly having a third endplate with a third plurality of protrusions and a fourth endplate with a fourth plurality of protrusions, wherein: the first plurality of protrusions are interdigitated with the second plurality of protrusions to telescope upon the lateral expansion and provide a substantially increased surface area for contact with an upper vertebral endplate in an intervertebral space; the third plurality of protrusions are interdigitated with the fourth plurality of protrusions to telescope upon the lateral expansion and provide a substantially increased surface area for contact with a lower vertebral endplate in an intervertebral space; and each of the first endplate, second endplate, third endplate, and fourth endplate have a plurality of receptacles for (i) receiving each of the respective plurality of protrusions upon a collapse of the device, and (ii) releasing each of the respective plurality of protrusions upon an expansion of the device.
20 . The laterally expandable fusion device of claim 19 , wherein: the first plurality of protrusions and the second plurality of protrusions slidably translate with a tongue-in-groove configuration to provide additional rigidity to the upper endplate assembly upon the lateral expansion; and the third plurality of protrusions and the fourth plurality of protrusions slidably translate with a tongue-in-groove configuration to provide additional rigidity to the lower endplate assembly upon the lateral expansion.

Description

CROSS REFERENCES TO RELATED APPLICATIONS This is a continuation of U.S. application Ser. No. 17/149,325, filed Jan. 14, 2021 and issued as U.S. Pat. No. 11,684,484 on Jun. 27, 2023, which is a continuation of U.S. application Ser. No. 16/290,428, filed Mar. 1, 2019 and issued as U.S. Pat. No. 11,285,018 on Mar. 29, 2022, which claims priority to U.S. Provisional Application No. 62/637,306, filed Mar. 1, 2018, each of which is hereby incorporated herein by reference in its entirety. BACKGROUND Field of the Invention The teachings herein are directed generally to medical devices and methods, including devices and methods for promoting an intervertebral fusion, such as devices that can be inserted in a subject in a collapsed state through a small surgical corridor, and the expand cephalocaudal only, transverse only, or in both directions, in which direction of expansion can also be obtained independently, if desired, after the insertion. Description of the Related Art The teachings provided herein include methods, devices, and systems for performing a spinal implant procedure on a subject. A spinal fusion is typically employed to eliminate pain caused by the motion of degenerated disk material. Upon successful fusion, a fusion device becomes permanently fixed within the intervertebral disc space. A common procedure for handling pain associated with intervertebral discs that have become degenerated due to various factors such as trauma or aging is the use of intervertebral fusion devices for fusing one or more adjacent vertebral bodies. Generally, to fuse the adjacent vertebral bodies, the intervertebral disc is first partially or fully removed. An intervertebral fusion device is then typically inserted between neighboring vertebrae to maintain normal disc spacing and restore spinal stability, thereby facilitating an intervertebral fusion. There are a number of known conventional fusion devices and methodologies in the art for accomplishing the intervertebral fusion. These include screw and rod arrangements, solid bone implants, and fusion devices which include a cage or other implant mechanism which, typically, is packed with bone and/or bone growth inducing substances. These devices are implanted between adjacent vertebral bodies in order to fuse the vertebral bodies together, alleviating the associated pain. However, there are challenges associated with the known conventional fusion devices and methodologies. For example, present methods for installing a conventional fusion device may require that the adjacent vertebral bodies be distracted to restore a diseased disc space to its normal or healthy height prior to implantation of the fusion device. In order to maintain this height once the fusion device is inserted, the fusion device is usually dimensioned larger in height than the initial distraction height. This difference in height may make it difficult for a surgeon to install the fusion device in the distracted intervertebral space. As such, there exists a need for a fusion device capable of being installed inside an intervertebral disc space at a minimum to no distraction height and for a fusion device capable of maintaining a normal distance between adjacent vertebral bodies when implanted. One of the most common post-operative complications of intervertebral fusion surgery is intervertebral graft or cage subsidence which are minimized or mitigated by using an intervertebral cage or graft of a larger footprint. This is often difficult because to minimize the trauma and morbidity associated with spine surgery, it is often advantageous to utilize the smallest surgical access corridor possible to achieve the goals of surgery. As such there exists a need for a fusion device capable of being inserted through a relatively small surgical corridor and capable to then be expanded to a larger footprint suitable to resist subsidence. It should be appreciated that a spinal fusion, for example, is a procedure that can be used to eliminate pain. This pain, for example, can be caused by the motion of degenerated disk material. Upon a successful fusion, a fusion device becomes permanently fixed within the intervertebral disc space. Unfortunately, the devices and procedures used in the art still suffer several problems, including those discussed above. One of skill will understand that the inventions described herein, however, address several of these problems including at least, for example, (i) a reduced surgical complexity and risk in an insertion of the device through the use of a minimum to minimal, or perhaps no, intervertebral distraction; (ii) a reduced surgical complexity and risk in an insertion of the device through a small surgical corridor; (iii) a desired width control in the expansion of the device through a variable transverse expansion system in a single device which provides for an on-the-fly selection of a desirable footprint, which can be a larger, or perhaps biased, footprint for achieving a desire