US-12616584-B2 - Expandable interbody implant with lordosis correction

Abstract

A spinal implant for placement between vertebral bodies includes a first member for engaging one of the vertebral bodies, a second member for engaging an opposing one of the vertebral bodies, and at least one extendable support element for inducing movement of the entire first member away from the second member. The first member is connected to the second member such that the first member moves away from the second member by a larger distance at a first end of the implant than at a second end of the implant. A connecting member may connect the first and second members together at the second end of the implant. The connecting member may include one or more rotatable linkages, or the connecting member may be an extension of one of the first and second members slidably received within a track defined within the other of the first and second members.

Inventors

• Amir Ali Sharifi-Mehr
• Oliver Buchert

Assignees

• VB Spine US Opoco LLC

Dates

Publication Date

20260505

Application Date

20230929

Claims (7)

1. 1 . A method of performing interbody fusion, the method comprising: positioning a spinal implant between a first vertebral body and a second vertebral body, wherein the spinal implant includes a first member having a first surface for engaging the first vertebral body and a second member having a second surface for engaging the second vertebral body; actuating one or more extendable support elements connected between the first and second members such that each of the one or more extendable support elements extends at the same rate with at least one of the extendable support elements actuated by a fluid; and inducing, based on the actuation of the at least one extendable support element, movement of the entire first member away from the second member at both a first end portion and a second end portion of the spinal implant, wherein the induced movement of the first member away from the second member is guided by a linkage, such that the first member moves away from the second member by a larger distance at the first end portion of the implant than at the second end portion of the implant.
2. 2 . The method of claim 1 , wherein the linkage is positioned at the second end portion of the implant such that the induced movement of the linkage guides the first member away from the second member by constraining the movement of the first member at a second end of the implant.
3. 3 . The method of claim 1 , wherein the at least one extendable support element is located at the first end portion of the spinal implant.
4. 4 . The method of claim 1 , further comprising inducing, based on the actuation of the at least one extendable support element, movement of the linkage.
5. 5 . The method of claim 1 , wherein the linkage is a rotatable linkage having a first end and a second end, the first end of the linkage being pivotably connected to the first member and the second end of the linkage being pivotably connected to the second member.
6. 6 . The method of claim 1 , wherein the linkage is a rotatable linkage.
7. 7 . The method of claim 1 , wherein the linkage is configured such that the first member rotates about a point spaced apart from the implant proximate the second end portion of the implant.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. patent application Ser. No. 17/158,499, filed Jan. 26, 2021, which is a continuation of U.S. patent application Ser. No. 15/599,638 filed May 19, 2017, now U.S. Pat. No. 10,940,018, which claims the benefit of the filing date of U.S. Provisional Patent Application No. 62/339,459 filed May 20, 2016, the disclosures of which are hereby incorporated herein by reference. BACKGROUND OF THE INVENTION Intervertebral implants are commonly used in spinal surgery, such as in interbody fusion procedures, in which an implant (e.g., a spacer or cage) is placed in the disc space between two vertebrae to be fused together. At least a portion of the disc is typically removed before the implant is positioned in the intervertebral space, and the implant may be supplemented with bone graft material to promote fusion of the vertebrae. Interbody fusion procedures may also be performed in conjunction with other types of fixation, such as pedicle screw fixation, to provide additional stability, particularly while the vertebrae fuse together. Different interbody fusion procedures can be distinguished by their location along the spine (e.g., in the cervical, thoracic, or lumbar regions); by the type of implant used; and by the surgical approach to the intervertebral space, in which different surgical approaches often imply different structural characteristics of the implant or implants used. Different surgical approaches to the spine include anterior, posterior, and lateral. Examples of interbody fusion techniques performed along a posterior approach include posterior lumbar interbody fusion (PLIF) and transforaminal lumbar interbody fusion (TLIF). PLIF techniques typically include positioning two intervertebral implants into the intervertebral space along a posterior to anterior direction, with one implant being positioned towards the left side of the spine and one implant being positioned towards the right side of the spine. The implants used in such PLIF techniques typically have a straight shape, in that they extend along a central axis. TLIF techniques, by contrast, typically include positioning one intervertebral implant into the intervertebral space (often towards the anterior portion of the intervertebral space) from the posterior of the patient, but the spine is approached on one side from a more lateral position than in PLIF techniques. The implants used in such TLIF techniques are often curved, such that they have an overall kidney bean-like shape. Interbody fusion techniques performed along a lateral approach, on the other hand, often involve implants that are generally symmetric along their linear longitudinal axis (e.g., having a substantially rectangular or oval shape), but the implants are typically larger than those used in PLIF or TLIF techniques. That is, intervertebral implants used in lateral approaches often cover a substantial portion of the disc space. Included among the different types of intervertebral implants are expandable implants. Such implants often have an initially contracted configuration, such that they have a low profile in the superior-inferior direction, in order to ease insertion into the intervertebral space. Such expandable implants can then be expanded in the superior-inferior direction after implantation, so as to securely engage and stabilize the vertebrae on both sides of the intervertebral space. Examples of such expandable intervertebral implants are disclosed in U.S. Pat. No. 8,992,620 (“the '620 patent”) and in U.S. patent application Ser. No. 15/481,854 filed on Apr. 7, 2017, entitled Expandable Interbody Implant (hereinafter “the '854 application”), the disclosures of which are hereby incorporated by reference herein as if fully set forth herein. Expandable intervertebral implants having certain similar features to those in the '620 patent and the '854 application are disclosed herein, and therefore some similar nomenclature is used herein for clarity and consistency. Although considerable effort has been devoted in the art to optimization of such intervertebral systems and methods, still further improvement would be desirable. BRIEF SUMMARY OF THE INVENTION The present invention relates to expandable interbody implants, as well as to methods of operating the same. Expandable interbody implants in accordance with aspects of the invention include opposing first and second surfaces for engaging respective vertebral bodies on each side of an intervertebral space, the first and second surfaces being located on respective first and second members. When the implants are expanded from a contracted configuration to an expanded configuration, the entire first member is moved away from the second member. The first member is desirably connected to the second member such that the first member moves away from the second member by a larger distance at a first end of the implant than at a second end of the implant