US-12616585-B2 - Stand-alone interbody fusion

US12616585B2US 12616585 B2US12616585 B2US 12616585B2US-12616585-B2

Abstract

Improved fixation or stabilization of implants is achieved via one or more deployable spikes or anchors. The deployable spikes or anchors may be present in the implant in a nested, collapsed, or retracted position while the implant is inserted into the human body, and may then be deployed (e.g., into adjacent bone) after the implant is in place, thereby fixing the implant's location against unwanted movement. Such fixation or stabilization of the implant may reduce patients' pain, may improve overall short-term and long-term stability of the implant, and may improve osteo-integration into the implant.

Inventors

David Hawkes
Peter Halverson
Jeffrey Ellis Harris
Jeffrey S. Hoskins

Assignees

Nexus Spine, LLC

Dates

Publication Date: 20260505
Application Date: 20240401

Claims (20)

1 . An implant comprising: an implant body adapted to be inserted into an interbody space between a first vertebral body and a second vertebral body of a spine, the implant body comprising: a cranial surface adapted to be disposed adjacent to the first vertebral body; and a caudal surface adapted to be disposed adjacent to the second vertebral body; an anchor cavity defined in an outer portion of the implant body, the outer portion of the implant body being disposed closer to an outer surface of the implant than to a center of at least one of the cranial surface and the caudal surface; a first anchor that is at least partially disposed in the anchor cavity and that is fully disposed in the outer portion of the implant body; and an inserter engagement formed at the outer surface of the implant, the inserter engagement being configured to receive an inserter configured to deploy the first anchor, wherein the first anchor comprises a first blade that is wider and taller than it is thick and that is configured to extend out of the anchor cavity at a constant angle that is within 10 degrees of orthogonal from at least one of the cranial surface and the caudal surface, wherein the first anchor is disposed proximate to the inserter engagement; and wherein the first blade extends across a midsagittal plane of the implant and is oriented generally orthogonal to the midsagittal plane of the implant.
2 . The implant of claim 1 , wherein the implant body further comprises a passage configured to be open to at least one of the first vertebral body and the second vertebral body, the passage being disposed between the cranial surface and the caudal surface, and wherein the anchor cavity is defined in the implant body between the passage and the outer surface of the implant body.
3 . The implant of claim 2 , wherein a lateral edge of the anchor cavity is disposed medial to a lateral edge of the passage.
4 . The implant of claim 1 , wherein the inserter engagement is proximate the first anchor and configured to receive both an inserter tool and a deployment tool.
5 . The implant of claim 1 , wherein the first anchor further comprises a second blade, and wherein the first blade is disposed closer to the outer surface than the second blade in the implant body.
6 . The implant of claim 1 , wherein the implant body comprises a biocompatible material, wherein the implant body comprises a stiffness of between 400 megapascals (MPa) and 1,200 MPa, and wherein the implant body defines pores having a size between 150 microns and 600 microns.
7 . The implant of claim 1 , wherein the implant body comprises a coil spring construction.
8 . The implant of claim 1 , wherein the implant body further comprises a second anchor that is configured to selectively extend from at least one of the cranial surface and the caudal surface, wherein the second anchor is at least partially disposed in the outer portion of the implant body, and wherein the first anchor is configured to move independently of the second anchor.
9 . The implant of claim 8 , wherein the first anchor and the second anchor comprise two discrete components that are configured to extend from the implant body in opposite directions.
10 . The implant of claim 1 , wherein the implant body defines the inserter engagement, and wherein the inserter engagement is formed by adjacent coil packs sweeping into each other to form a detent without a solid geometry that would alter a stiffness of the implant body.
11 . An implant comprising: an implant body adapted to be inserted into an interbody space between a first vertebral body and a second vertebral body of a spine, the implant body comprising: a cranial surface adapted to be disposed adjacent to the first vertebral body; a caudal surface adapted to be disposed adjacent to the second vertebral body; and an anchor comprising: a first blade; and a second blade, wherein at least one of the first blade and the second blade extends across a midsagittal plane and is disposed generally orthogonal to the midsagittal plane, wherein the first blade and the second blade are configured to extend together from either the cranial surface or the caudal surface, and wherein the first blade and the second blade are monolithically formed as a single unit to form the anchor.
12 . An implant comprising: an implant body adapted to be inserted into an interbody space between a first vertebral body and a second vertebral body of a spine, the implant body comprising: a cranial surface adapted to be disposed adjacent to the first vertebral body; a caudal surface adapted to be disposed adjacent to the second vertebral body; a ventral surface comprising an inserter-engagement, the ventral surface extending laterally across a ventral portion of the implant body; an anchor cavity defined in the implant body; a first anchor that is at least partially disposed in the anchor cavity; and an anchor deployment feature formed at an outer surface of the implant body, the anchor deployment feature being configured to receive an instrument configured to interact with the anchor deployment feature at the outer surface to deploy the first anchor, wherein the first anchor is configured to extend out of the anchor cavity and from at least one of the caudal surface and the cranial surface while maintaining a constant angle with respect to the at least one of the caudal surface and the cranial surface, wherein the constant angle with respect to the at least one of the caudal surface and the cranial surface is within 10 degrees of orthogonal to the at least one of the caudal surface and the cranial surface, wherein the first anchor comprises a blade that is wider and taller than it is thick, and wherein a width of the first anchor extends laterally across a portion of the implant body.
13 . The implant of claim 12 , wherein the constant angle with respect to the at least one of the caudal surface and the cranial surface is within 4 degrees of orthogonal to the at least one of the caudal surface and the cranial surface, and wherein the first anchor is disposed closer to the outer surface of the implant body than to a middle of the implant body.
14 . The implant of claim 12 , wherein the constant angle with respect to the at least one of the caudal surface and the cranial surface is orthogonal to the at least one of the caudal surface and the cranial surface.
15 . The implant of claim 14 , wherein an orientation of the blade is fixed orthogonal to a midsagittal plane of the implant body.
16 . The implant of claim 12 , wherein an orientation of the blade is fixed orthogonal to a midsagittal plane of the implant body.
17 . An implant comprising: an implant body adapted to be inserted into an interbody space between a first vertebral body and a second vertebral body of a human spine, the implant body comprising: a cranial surface adapted to be disposed adjacent to the first vertebral body; a caudal surface adapted to be disposed adjacent to the second vertebral body; an outer surface comprising an inserter engagement disposed across a midsagittal plane of the implant body; a passage configured to be open to at least one of the first vertebral body and the second vertebral body, the passage being disposed between the cranial surface and the caudal surface: an anchor cavity defined in the implant body between the passage and the outer surface; a first anchor that is at least partially disposed in the anchor cavity; and a second anchor that is configured to selectively extend from the implant body, wherein the first anchor comprises a first blade that is configured to extend out of the anchor cavity from and within 10 degrees of orthogonal to at least one of the caudal surface and the cranial surface and generally orthogonal to the midsagittal plane of the implant body, and wherein the first anchor and the second anchor comprise two discrete components.
18 . The implant of claim 17 , wherein a thickness of the first blade extends between the passage and the outer surface, wherein the first blade is taller and wider than it is thick, and wherein the first blade is configured to extend out of a slot formed in the at least one of the caudal surface and the cranial surface.
19 . The implant of claim 17 , wherein an angle of the first blade in a deployed configuration is equal to an angle of the first blade in an undeployed configuration.
20 . An implant comprising: an implant body adapted to be inserted into an interbody space between a first vertebral body and a second vertebral body of a human spine, the implant body comprising: a cranial surface adapted to be disposed adjacent to the first vertebral body; a caudal surface adapted to be disposed adjacent to the second vertebral body; a ventral surface extending between the cranial surface and the caudal surface at a ventral portion of the implant body, the ventral surface comprising an inserter engagement; an anchor cavity defined in the ventral portion of the implant body; a first anchor that is at least partially disposed in the anchor cavity, the first anchor comprising a first blade with a first width, a first height, and a first thickness, the first width and the first height each being greater than the first thickness; and a second anchor comprising a second blade with a second width, a second height, and a second thickness, the second width and the second height each being greater than the second thickness, wherein the first anchor is configured to extend from the cranial surface, and the second anchor is configured to extend from the caudal surface, wherein each of the first anchor and the second anchor extends across a midsagittal plane of the implant body, wherein the first anchor is configured to extend from the cranial surface along an axis of movement that is generally parallel to an axis of movement of the second anchor as the second anchor extends from the caudal surface, and wherein the first anchor and the second anchor are both positioned in a ventral half of the implant.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. patent application Ser. No. 16/297,290, entitled Stand-Alone Interbody Fusion, and filed Mar. 8, 2019, which claims the benefit of: U.S. Provisional Application No. 62/640,556, entitled Stand-Alone Interbody Fusion, and filed Mar. 8, 2018; U.S. Provisional Application No. 62/689,703, entitled Stable-C Standalone Interbody, and filed Jun. 25, 2018; and U.S. Provisional Application No. 62/689,707, entitled Interbody Inserter, and filed Jun. 25, 2018, with each and every one of the foregoing applications being incorporated herein by reference, in their entireties, and for all they disclose. This application is related to U.S. patent application Ser. No. 15/372,290, entitled Porous Interbody Spacer, and filed Dec. 7, 2016, which is incorporated herein by reference for all it discloses. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to spinal fusion implants, and more particularly to a porous interbody spacer having features increasing stabilization of the implants in the disc space. 2. Background and Related Art Human bones are generally formed of two types of structural bone tissue: cortical bone and trabecular or cancellous bone. Cortical bone generally forms the outer shell of most bones, and is more dense, harder, stronger, and stiffer than trabecular bone. Trabecular bone is typically found at the ends of long bones proximal to joints, as well as in the interior of vertebrae. Trabecular bone is highly vascularized and has a generally porous or spongy structure through which blood vessels pass. Generally, trabecular bone has pores that are on the order of 150 to 650 microns in size. Not all trabecular bone has the same porosity: different bones have different trabecular bone porosity. The physical characteristics of bone are important for physiological purposes related to the growth and formation of bone both originally as well as during the healing process. The cells responsible for bone growth, including osteocytes and osteoblasts, work together to form bone as needed within the body, but will only form bone under proper conditions, including when the cells experience proper loads and stresses, when a network of blood vessels is available to supply needed nutrients, and when gaps to be filled by bone are of a proper size. When proper conditions are not available, bone cannot or will not grow. For example, when bone does not experience loading, it will not grow and can even be resorbed. Additionally, when gaps to be filled are too large or too small, bone cannot bridge the gap and will not grow. In addition to proper physical conditions, bone growth only occurs when certain conditions are met. First, there must be a kernel of living bone to start the process. The living bone supplies the cells necessary for bone growth and formation. Additionally, a cascade of chemical triggers is required for bone to grow. Finally, because bone growth is impeded by the presence of certain materials and/or chemicals, an absence of such materials and chemicals is required for proper bone growth. One example of where it is generally recognized as advantageous to promote bone growth is in the orthopedic implant industry. One goal with many orthopedic implants is for bone growth at the interface to fuse or secure the implant to the bone. For this reason, many orthopedic implants are provided with a porous surface at the bone-implant interface, with the expectation that bone will grow into the porous surface of the implant. Other implants may be provided with one or more cavities or voids to receive bone growth (e.g., a graft window), and during surgery any such cavities or voids may be filled with a material intended to promote bone growth, including morcellized bone graft material. These techniques have been used in implants for years with varying degrees of success, but the success of such devices has been limited by the devices' ongoing failure to provide physical and chemical characteristics most conducive to bone growth. Even when a graft is present in a cavity or void, any bone that does form on or around the device is of lesser quality and quantity. Generally, current implants have one or more characteristics that are not maximally conducive to facilitating bone growth into the implant. For example, some implants may provide a pore size that is generally within a desirable range, but may have a stiffness that is too high to allow bone within the porous structure of the implant to be properly loaded. As a result, the bone will not take advantage of the correct porosity and pore size of such implants, and will grow only minimally, if at all, in the porous structure of such implants. In other implants, the stiffness may be generally within a desirable range, but in order to achieve the desired stiffness, the device manufacturer creates pores that are too large or too small to facilitate proper bone growth