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US-20260124044-A1 - SPINAL IMPLANT HAVING COMPLIANT SURFACE

US20260124044A1US 20260124044 A1US20260124044 A1US 20260124044A1US-20260124044-A1

Abstract

The invention involves an interbody implant (spacer) and a method of manufacturing an interbody implant for use in spinal procedures, having one or more compliant surfaces to more evenly distribute the load applied to the bone while in use, as well as aid in bone growth and attachment. The interbody spacer has one or more unique surfaces designed to comply (flex) upon receiving a predetermined load. By flexing, the surface contact area between the implant and the bone is increased to distribute the load over a larger area. In order to provide the flexing, at least a portion of the implant is constructed from a plurality of bar springs that are interconnected or integrally connected with each other to conform to a surface while providing sufficient support for use as an implant.

Inventors

  • Christopher Walsh
  • Brian A. O'Shaughnessy

Assignees

  • Integrity Intellect Inc.

Dates

Publication Date
20260507
Application Date
20251031

Claims (16)

  1. 1 . An interbody implant ( 100 ) comprising: a bottom surface ( 10 ), a top surface ( 12 ), a front surface ( 14 ), a rear surface ( 16 ) and side surfaces ( 18 ), the surfaces formed integral with respect to each other and constructed and arranged to provide compliance so that the surface contact area between the implant ( 100 ) and a bone surface is increased when compared to a non-compliant implant.
  2. 2 . The interbody implant of claim 1 wherein at least the bone contacting surfaces include a first layer of bar springs ( 20 ), each bar spring ( 20 ) is secured at one distal end ( 26 ) to a non-compliant structure, the uppermost surface ( 28 ) of the bar springs ( 20 ) providing a surface that can flex and comply with an adjacently positioned bone surface.
  3. 3 . The interbody implant of claim 2 wherein the bar springs ( 20 ) are secured at both ends to the non-compliant structure.
  4. 4 . The interbody implant of claim 2 wherein a second end of each bar spring ( 20 ) is secured to a compliant structure.
  5. 5 . The interbody implant of claim 4 wherein the compliant structure is a second layer of bar springs ( 20 ), the second layer of bar springs ( 20 ) positioned adjacent to the first layer of bar springs ( 20 ).
  6. 6 . The interbody implant of claim 1 wherein at least the bone contacting surfaces include bar springs ( 20 ), each bar spring ( 20 ) is secured at both distal ends ( 26 ) to a non-compliant structure, the uppermost surface ( 28 ) of the bar springs ( 20 ) providing a surface that can flex and comply with an adjacently positioned bone surface.
  7. 7 . The interbody implant of claim 5 wherein both ends of each bar spring ( 20 ) are secured to a compliant structure.
  8. 8 . The interbody implant of claim 6 wherein the compliant structure is a second layer of bar springs ( 20 ), the second layer of bar springs ( 20 ) positioned adjacent to the first layer of bar springs ( 20 ).
  9. 9 . The interbody implant of claim 2 wherein each bar spring ( 20 ) is formed to include an arch shape ( 24 ).
  10. 10 . The interbody implant of claim 9 wherein each bar spring ( 20 ) includes a predetermined spring rate.
  11. 11 . The interbody implant of claim 2 including more than one layer of bar springs ( 20 ).
  12. 12 . The interbody implant of claim 11 wherein the bar springs ( 20 ) are arranged in layers, one layer adjacent to the other.
  13. 13 . The interbody implant of claim 12 wherein the distal ends of the first layer of bar springs ( 20 ) are connected to the bar springs ( 20 ) of a second layer of bar springs ( 20 ).
  14. 14 . The interbody implant of claim 2 wherein the spring material is selected from the group consisting of polyetheretherketone (PEEK), polyaryletherketone (PEAK) or polyetherimide (PEI).
  15. 15 . The interbody implant of claim 2 wherein the spring material is titanium.
  16. 16 . The interbody implant of claim 12 wherein each layer is oriented in an angular relationship with respect to an adjacent layer to provide different compliance characteristics.

Description

RELATED APPLICATIONS In accordance with 37 C.F.R 1.76, a claim of priority is included in an Application Data Sheet filed concurrently herewith. Accordingly, under 35 U.S.C. §119(e), the present invention claims priority of U.S. Patent Application No. 63/716,062, entitled “SPINAL IMPLANT HAVING COMPLIANT SURFACE”, filed on November 4, 2024. The contents of the above referenced application are herein incorporated by reference in its entirety. FIELD OF INVENTION The present invention relates to bone fixation devices and procedures for the placement of these devices in an individual. More particularly, the present invention relates to a device for use in spinal fusion having a compliant structure to provide more even force loading to the surrounding bone structure. BACKGROUND INFORMATION Medical procedures often require the use of surgical hardware. In spine related surgeries, a common type of surgical hardware used by surgeons is an interbody implant. Typical interbody implants are constructed from very rigid materials, e.g. plastics, having the compressive strength of steel or titanium alloys, also having extremely high compression ratings. Thus, the implants are rigid and inflexible under the normal loads exerted on the bones of an in-vivo human or other animal. The implants are inserted into various portions or anatomical features of the spine, including in the cervical, thoracic, lumbar, sacroiliac joints, and facets. The implants are generally constructed to cover as much bone surface as is possible with a particular procedure for distribution of the load applied to the bone. Thus, different procedures have been developed in an attempt to provide the most stability to the implant and reduce damage to soft tissue during the procedure. For example, the degeneration of the intervertebral disk, in particular, the degeneration of the nucleus pulposus, results in a loss of height in the affected disk space which is associated with a weakening of the annulus fibrosus and of the ligaments. As a consequence, the spinal column becomes instable and is more susceptible to horizontal displacement of the vertebral bodies with respect to one another. This horizontal or vertical movement of vertebral bodies results in impairments of the nerve roots in this region and/or of the spinal marrow, with pain resulting therefrom. The principle treatment of these symptoms consists of the surgical removal of the nucleus pulposus and the insertion of support bodies in order to restore the normal height of the disk space. While there are a number of traditional systems and methods for inserting support bodies, there are a variety of demands on both the surgeon performing an intervertebral disk procedure and on the spinal spacers themselves. A Transforaminal Lumbar Interbody Fusion (TLIF) is a surgical procedure that uses a posterior and lateral approach to access the disc space and insert a spacer. To gain access to the disc space, typically, a facet joint is removed and access is gained via the nerve foramen. While more technically demanding of the surgeon than other fusion techniques, a TLIF offers a number of clinical advantages. When compared to a Posterolateral Fusion (PLF), a TLIF approach leaves much more of the soft tissue intact, which is less traumatic for the patient. Further, a PLF does not provide access to the disc space. While a Posterolateral Interbody Fusion (PLIF) provides access to the disc space, a TLIF approach also provides access to the interbody space, but without the need for manipulation of neural elements, reducing the risk of post-operative neural deficit. Additionally, in a TLIF, only a single spacer is placed. More specifically, the TLIF spacer is placed in the anterior aspect of the disc space, thus providing space for a substantial fusion mass in the posterior aspect of the disc space where the natural compression occurs. An OLIF (oblique lateral interbody fusion) procedure minimizes the cutting of muscles and uses a single port to access the disc space and fill the interbody implant with bone material to fuse the bones. An XLIF (extreme lateral interbody fusion) is a minimally invasive procedure using an approach from the side of the lower back. This procedure is also referred to as LLIF (lateral lumbar interbody fusion) and DLIF (direct lateral interbody fusion. XLIF does not require entry through sensitive back muscles, bones or ligaments. This typically results in less pain after surgery. An ALIF (anterior lumbar interbody fusion) approach has several advantages but involves a major abdominal incision. The technique allows direct view of the disc space and vertebral bodies which permits easier cleaning of the disc space. In addition, the back and lateral muscles are spared from damage during the procedure, reducing postoperative pain. However, all of these procedures suffer from a similar shortcoming. In particular, the surfaces of the bone where the implant(s) is/are placed are often not flat an