# US 10,945,857 B2 · Bilaterally expanding intervertebral body fusion device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,945,857 B2 - Document ID: US10945857B2 - Status: Granted - Kind: B2 - Application number: 16/158,024 - Filed: 2018-10-11 - Published: 2019-03-14 - Granted: 2021-03-16 - Earliest claimed: 2014-06-04 - Assignees: Wenzel Spine, Inc. - Applicants: Wenzel Spine, Inc. - Inventors: Erik Emstad - Web page: https://patentgrep.com/patent/US10945857B2 ## CPC - A61F 2/446: {having a circular or elliptical cross-section substantially parallel to the axis of the spine, e.g. cylinders or frustocones} - A61F 2/30771: {applied in original prostheses, e.g. holes or grooves} - A61F 2/4455: {for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages (intervertebral discs A61F2/442)} - A61F 2/447: {substantially parallelepipedal, e.g. having a rectangular or trapezoidal cross-section} - A61F 2/4611: {of spinal prostheses} - A61F 2/4405: {for apophyseal or facet joints, i.e. between adjacent spinous or transverse processes (devices implanted between spinous or transverse processes A61B17/7062)} - A61F 2/4603: {for insertion or extraction of endoprosthetic joints or of accessories thereof} - A61F 2002/30224: {cylindrical} - A61F 2002/30515: {using a locking wedge or block} - A61F 2002/30538: {for adjusting angular orientation} - A61F 2002/30545: {for adjusting a diameter} - A61F 2002/30556: {for adjusting thickness} - A61F 2002/30593: {hollow} - A61F 2002/3085: {with a threaded, e.g. self-tapping, bone-engaging surface, e.g. external surface} - A61F 2002/30904: {serrated profile, i.e. saw-toothed} - A61F 2002/3093: {for promoting ingrowth of bone tissue} - A61F 2002/4615: {of spacers} - A61F 2002/4627: {with linear motion along or rotating motion about the instrument axis or the implantation direction, e.g. telescopic, along a guiding rod, screwing inside the instrument} - A61F 2002/4629: {connected to the endoprosthesis or implant via a threaded connection} - A61F 2230/0067: conical - A61F 2230/0069: cylindrical - A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C) ## Abstract An embodiment includes an expandable intervertebral body fusion device with two expansion wedges within a generally hollow main body. After implantation into the intervertebral disc space, the expansion wedges are simultaneously moved from the center of the device toward the ends, which flexes the arms of the cage and increases the size of the implant. This expansion stabilizes the device in the disc space and increases the disc height, thereby reducing foraminal compression of spinal nerves and creating a stable motion segment for eventual fusion. Other embodiments are described herein. ## Claims ### Claim 1 An intervertebral spacing implant system comprising: a first seat having a first lateral end; first branches coupled to the first lateral end of the first seat and extending in a first lateral direction away from the first seat, the first seat and the first branches forming a first cage defining a first internal volume, each first branch having a first inward side and a first outward side; a first spacer configured to fit within the first cage and move in the first lateral direction upon the urging of a spacer-advancing instrument, the first spacer and the first cage configured such that one or more of the first branches will move from an unextended position to an extended position when the first spacer is moved upon the urging of the spacer-advancing instrument; a first shoulder formed on one of the first inward sides, the first shoulder configured to reversibly secure the first spacer; wherein the first internal volume between the first lateral end of the first seat and the first spacer is unoccupied by any link member when the first spacer is secured by the first shoulder; a second seat having a second lateral end; second branches coupled to the second lateral end of the second seat and extending in a second lateral direction away from the second seat, the second seat and the second branches forming a second cage defining a second internal volume, each second branch having a second inward side and a second outward side; a second spacer configured to fit within the second cage and move upon the urging of at least one of the spacer-advancing instrument or an additional spacer-advancing instrument, the second spacer and the second cage configured such that one or more of the second branches will move from an unextended position to an extended position when the second spacer is moved upon the urging of the at least one of the spacer-advancing instrument or the additional spacer-advancing instrument; a second shoulder formed on one of the second inward sides, the second shoulder configured to reversibly secure the second spacer; wherein the first seat, the first branches, the second seat, and the second branches collectively form a second unitary structure. ### Claim 2 (depends on 1) The intervertebral spacing implant system of claim 1, wherein the first branches are configured to enable bilateral expansion of the implant and the second branches are configured to enable bilateral expansion of the implant. ### Claim 3 (depends on 2) The intervertebral spacing implant system of claim 2, wherein: the first inward side of each first branch is smooth and is not threaded, and the second inward side of each second branch is smooth and is not threaded. ### Claim 4 (depends on 3) The intervertebral spacing implant system of claim 3 wherein the first seat, the first spacer, and two of the first branches define a slot when the one or more of the first branches are in an extended position. ### Claim 5 (depends on 4) The intervertebral spacing implant system of claim 4, wherein the first branches comprise three or more branches and the second branches comprise three or more branches. ### Claim 6 (depends on 5) The intervertebral spacing implant system of claim 5, wherein the first spacer is included within the first cage and the second spacer is included within the second cage. ### Claim 7 (depends on 6) The intervertebral spacing implant system of claim 6, wherein: the one or more of the first branches that move from an unextended position to an extended position further comprise the first shoulder; the one or more of the second branches that move from an unextended position to an extended position comprise the second shoulder. ### Claim 8 (depends on 7) The intervertebral spacing implant system of claim 7, wherein the first spacer comprises a first connector to removably couple the first spacer to the spacer-advancing instrument. ### Claim 9 (depends on 8) The intervertebral spacing implant system of claim 8 comprising the spacer-advancing instrument, wherein the spacer-advancing instrument is configured to simultaneously advance the first and second spacers. ### Claim 10 (depends on 8) The intervertebral spacing implant system of claim 8 comprising the spacer-advancing instrument, wherein the spacer-advancing instrument is configured to asynchronously and simultaneously advance the first and second spacers. ### Claim 11 (depends on 8) The intervertebral spacing implant system of claim 8, wherein first lateral ends of two or more first branches connect to one another and second lateral ends of two or more of the second branches connect to one another. ### Claim 12 (depends on 8) The intervertebral spacing implant system of claim 8, wherein: a long axis extends centrally within the first and second cages along the first and second lateral directions; one of the first branches deflects radially a first distance, orthogonal to the long axis, when the first spacer is secured by the first shoulder; another of the first branches deflects radially a second distance, orthogonal to the long axis, when the first spacer is secured by the first shoulder; the first distance is unequal to the second distance. ### Claim 13 (depends on 1) The intervertebral spacing implant system of claim 1 comprising the spacer-advancing instrument, wherein the spacer-advancing instrument is configured to simultaneously advance the first and second spacers. ### Claim 14 (depends on 13) The intervertebral spacing implant system of claim 13, wherein the first branches are configured to enable bilateral expansion of the implant and the second branches are configured to enable bilateral expansion of the implant. ### Claim 15 (depends on 14) The intervertebral spacing implant system of claim 14, wherein: the first inward side of each first branch is smooth and is not threaded, and the second inward side of each second branch is smooth and is not threaded. ### Claim 16 (depends on 1) The intervertebral spacing implant system of claim 1 comprising the spacer-advancing instrument, wherein the spacer-advancing instrument is configured to asynchronously and simultaneously advance the first and second spacers. ### Claim 17 (depends on 16) The intervertebral spacing implant system of claim 16, wherein the first branches are configured to enable bilateral expansion of the implant and the second branches are configured to enable bilateral expansion of the implant. ### Claim 18 An intervertebral spacing implant system comprising: a first seat having a first lateral end; first branches coupled to the first lateral end of the first seat and extending in a first direction away from the first seat, the first seat and the first branches forming a first cage defining a first internal volume, each first branch having a first inward side and a first outward side; a first spacer configured to fit within the first cage and move in the first direction upon the urging of a spacer-advancing instrument, the first spacer and the first cage configured such that one or more of the first branches will move from an unextended position to an extended position when the first spacer is moved upon the urging of the spacer-advancing instrument; a first shoulder formed on one of the first inward sides, the first shoulder configured to reversibly secure the first spacer; wherein the first internal volume between the first lateral end of the first seat and the first spacer is unoccupied by any link member when the first spacer is secured by the first shoulder; a second seat having a second lateral end; second branches coupled to the second lateral end of the second seat and extending in a second direction away from the second seat, the second seat and the second branches forming a second cage defining a second internal volume, each second branch having a second inward side and a second outward side; a second spacer configured to fit within the second cage and move upon the urging of the spacer-advancing instrument, the second spacer and the second cage configured such that one or more of the second branches will move from an unextended position to an extended position when the second spacer is moved upon the urging of the spacer-advancing instrument; a second shoulder formed on one of the second inward sides, the second shoulder configured to reversibly secure the second spacer; wherein the first seat, the first branches, the second seat, and the second branches collectively form a unitary structure. ### Claim 19 (depends on 18) The intervertebral spacing implant system of claim 18, wherein the first branches are configured to enable bilateral expansion of the implant and the second branches are configured to enable bilateral expansion of the implant. ### Claim 20 (depends on 19) The intervertebral spacing implant system of claim 19 comprising the spacer-advancing instrument, wherein the spacer-advancing instrument is configured to simultaneously advance the first and second spacers.