# US 8,540,721 B2 · Adjustable apparatus and methods for inserting an implant > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,540,721 B2 - Document ID: US8540721B2 - Status: Granted - Kind: B2 - Application number: 13/079,142 - Filed: 2011-04-04 - Published: 2012-10-04 - Granted: 2013-09-24 - Earliest claimed: 2011-04-04 - Assignees: Amicus Design Group, LLC - Applicants: Randall F. Lee; Michael J. Mojica - Inventors: Randall F. Lee; Michael J. Mojica - Web page: https://patentgrep.com/patent/US8540721B2 ## CPC - A61F 2/44: for the spine, e.g. vertebrae or spinal discs - A61B 17/025: {Joint distractors} - A61F 2/4611: {of spinal prostheses} - A61B 2017/0256: {for the spine} - A61F 2/4603: {for insertion or extraction of endoprosthetic joints or of accessories thereof} - 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 2002/4687: {Mechanical guides for implantation instruments} - A61F 2002/4696: {optical} - 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) - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract Methods and apparatus for inserting an implant into an intervertebral cavity between adjacent vertebral bodies provide for: adjust an initial height between inner surfaces of respective first and second ramps of an inserter; simultaneously sliding first and second ramps of the inserter, and the implant, proximally, toward distal ends of the first and second ramps, such that the vertebral contact surfaces of the respective first and second ramps separate and distract the vertebral bodies and receive the implant into the intervertebral space with no compressive loading, while holding an initial angle between the ramps substantially constant; reversing the sliding of the first and second ramps to permit the vertebral bodies to compressively load the implant, again while holding the initial angle therebetween substantially constant; and withdrawing the distal ends of the first and second ramps from the intervertebral space. ## Claims ### Claim 1 An instrument for inserting an implant into a vertebral space, comprising: first and second ramps, each including: (i) opposing outer and inner surfaces, each extending between proximal and distal ends thereof, and (ii) a vertebral contact surface located at the distal end thereof and in opposing relation to the inner surface thereof; and a ramp adjustment assembly having multiple elements in sliding contact with one another and being disposed between the inner surfaces of the first and second ramps, the ramp adjustment assembly operating to: (i) establish an initial non-zero angle between the vertebral contact surfaces of the respective first and second ramps; (ii) adjust an initial height between the inner surfaces of the respective first and second ramps, measured at the ramp adjustment assembly, by way of sliding at least two of the multiple elements in opposing directions relative to one another whilst remaining between the first and second ramps; and (iii) separate the vertebral contact surfaces of the respective first and second ramps, while holding the initial angle and the initial height substantially constant, via simultaneous sliding advancement of the ramp adjustment assembly toward the distal ends of the first and second ramps. ### Claim 2 An instrument for inserting an implant into a vertebral space, comprising: first and second ramps, each including: (i) opposing outer and inner surfaces, each extending between proximal and distal ends thereof, and (ii) a vertebral contact surface located at the distal end thereof and in opposing relation to the inner surface thereof; and first and second wedges, each including: (i) a base side oriented toward the inner surface of a respective one of the first and second ramps, and defining a reference plane, (ii) an incline side defining a sliding plane that is at an acute angle to the reference plane, and (iii) a wedge coupling element operating to slidingly engage the incline side of the other of the first and second wedges, such that the sliding planes of the first and second wedges slide parallel to one another, wherein at least one of the first and second wedges includes a ramp coupling element located proximate to the base side thereof and operating to slidingly engage a respective one of the first and second ramps such that the reference plane slides substantially parallel thereto. ### Claim 3 (depends on 2) The instrument of claim 2, wherein the first and second wedges operate to establish an initial angle between the vertebral contact surfaces of the respective first and second ramps. ### Claim 4 (depends on 2) The instrument of claim 2, wherein sliding the first and second wedges relative to one another along the sliding planes thereof operates to adjust an initial height between the inner surfaces of the respective first and second ramps. ### Claim 5 (depends on 2) The instrument of claim 2, wherein simultaneous sliding advancement of the first and second wedges toward the distal ends of the first and second ramps, by way of the respective ramp coupling elements, separates the vertebral contact surfaces of the respective first and second ramps while holding the initial angle therebetween substantially constant. ### Claim 6 (depends on 2) The instrument of claim 2, wherein: a proximal-distal axis is defined by the proximal and distal ends of the first and second ramps; each of the sliding planes of the first and second wedges define a normal vector thereto; the normal vector of the sliding plane of one of the first and second wedges includes a component directed distally along the proximal-distal axis but no component directed proximally along the proximal-distal axis; and the normal vector of the sliding plane of the other of the first and second wedges includes a component directed proximally along the proximal-distal axis but no component directed distally along the proximal-distal axis. ### Claim 7 (depends on 6) The instrument of claim 6, wherein the reference planes, sliding planes, and acute angles of the first and second wedges are designed such that the initial angle between the vertebral contact surfaces of the first and second ramps is between about 0 and 45 degrees. ### Claim 8 (depends on 7) The instrument of claim 7, wherein the initial angle between the vertebral contact surfaces of the first and second ramps is about 11 degrees. ### Claim 9 (depends on 2) The instrument of claim 2, wherein the wedge coupling elements include one or more tongue-and-groove couplings operating to complementarily engage one another such that the incline side of the first wedge slidingly engages the incline side of the second wedge and the sliding planes of the first and second wedges slide parallel to one another. ### Claim 10 (depends on 2) The instrument of claim 2, wherein the ramp coupling elements include one or more tongue-and-groove couplings operating to complementarily engage one another, such that the base side of the first wedge slidingly engages the first ramp, and the base side of the second wedge slidingly engages the second ramp. ### Claim 11 (depends on 2) The instrument of claim 2, wherein: a proximal-distal axis is defined by the proximal and distal ends of the first and second ramps; one of the first and second wedges includes a bore extending therethrough in a direction substantially parallel to the proximal-distal axis; the instrument further comprises: (i) a rod extending through, and slideable within, the bore; and (ii) a stop element disposed at a distal end of the rod and operating to prevent the other of the first and second wedges from moving along the proximal-distal axis with respect to the rod; an actuator operating to slide the one of the first and second wedges on the rod and along the proximal-distal axis, thereby causing the first and second wedges to move relative to one another along the sliding planes thereof, and to adjust the initial height of the first and second ramps. ### Claim 12 (depends on 11) The instrument of claim 11, wherein the stop element operates to permit the other of the first and second wedges to slide in a direction transverse to the proximal-distal axis in reaction to the actuator sliding the one of the first and second wedges on the rod along the proximal-distal axis. ### Claim 13 (depends on 12) The instrument of claim 12, further comprising one or more tongue-and-groove couplings operating to slidingly connect the stop element and the other of the first and second wedges such that the stop element operates to permit the other of the first and second wedges to slide in the direction transverse to the proximal-distal axis in reaction to the one of the first and second wedges sliding on the rod along the proximal-distal axis. ### Claim 14 (depends on 13) The instrument of claim 13, wherein the one or more tongue-and-groove couplings operate to prevent the other of the first and second wedges from moving away from the stop element proximally or distally along the proximal-distal axis. ### Claim 15 (depends on 11) The instrument of claim 11, wherein the actuator includes: a threaded portion of the rod; and a nut in threaded engagement with the threaded portion of the rod such that rotation of the nut advances an engagement element thereof to move the one of the first and second wedges on the rod and along the proximal-distal axis. ### Claim 16 (depends on 11) The instrument of claim 11, further comprising calibration markings on at least one of the first and second wedges providing a calibrated visual indication of the relative movement of the first and second wedges and resultant adjustment of the initial height of the first and second ramps. ### Claim 17 An instrument for inserting an implant into a vertebral space, comprising: first and second ramps, each including: (i) opposing outer and inner surfaces, each extending between proximal and distal ends thereof, and (ii) a vertebral contact surface located at the distal end thereof and in opposing relation to the inner surface thereof; first and second wedges, each including: (i) a base side oriented toward the inner surface of a respective one of the first and second ramps, and defining a reference plane, (ii) an incline side defining a sliding plane that is at a first acute angle to the reference plane, and (iii) a ramp coupling element located proximate to the base side and operating to slidingly engage a respective one of the first and second ramps such that the reference plane slides substantially parallel thereto; and a third wedge including: (i) first and second opposing incline sides, each defining a respective first and second sliding plane, which are at a second acute angle with respect to one another, (ii) first and second wedge coupling elements, each operating to slidingly engage a respective one of the incline sides of the first and second wedges, such that the first sliding plane of the third wedge slides parallel to the sliding plane of the first wedge, and such that the second sliding plane of the third wedge slides parallel to the sliding plane of the second wedge. ### Claim 18 (depends on 17) The instrument of claim 17, wherein the first, second, and third wedges operate to establish an initial angle between the vertebral contact surfaces of the respective first and second ramps. ### Claim 19 (depends on 17) The instrument of claim 17, wherein sliding the third wedge relative to the first and second wedges operates to adjust an initial height between the inner surfaces of the respective first and second ramps. ### Claim 20 (depends on 17) The instrument of claim 17, wherein simultaneous sliding advancement of the first, second, and third wedges toward the distal ends of the first and second ramps, by way of the respective ramp coupling elements, separates the vertebral contact surfaces of the respective first and second ramps while holding the initial angle therebetween substantially constant. ### Claim 21 (depends on 17) The instrument of claim 17, wherein: a proximal-distal axis is defined by the proximal and distal ends of the first and second ramps; the third wedge includes a bore extending therethrough in a direction substantially parallel to the proximal-distal axis; the instrument further comprises: (i) a rod extending through, and slideable within, the bore; and (ii) a stop element disposed at a distal end of the rod and operating to prevent the first and second wedges from moving along the proximal-distal axis with respect to the rod; an actuator operating to slide the third wedge on the rod and along the proximal-distal axis, thereby causing the third wedge to move relative to the first and second wedges along the sliding planes thereof, and to adjust the initial height of the first and second ramps. ### Claim 22 (depends on 21) The instrument of claim 21, wherein the stop element operates to permit the first and second wedges to slide in opposite directions transverse to the proximal-distal axis in reaction to the actuator sliding the third wedge on the rod along the proximal-distal axis. ### Claim 23 (depends on 22) The instrument of claim 22, further comprising one or more tongue-and-groove couplings operating to slidingly connect the stop element and the first and second wedges such that the stop element operates to permit the first and second wedges to slide in the opposite directions transverse to the proximal-distal axis in reaction to the third wedge sliding on the rod along the proximal-distal axis. ### Claim 24 (depends on 23) The instrument of claim 23, wherein the one or more tongue-and-groove couplings operate to prevent the first and second wedges from moving away from the stop element proximally or distally along the proximal-distal axis. ### Claim 25 (depends on 21) The instrument of claim 21, wherein the actuator includes: a threaded portion of the rod; and a nut in threaded engagement with the threaded portion of the rod such that rotation of the nut advances an engagement element thereof to move the third wedge on the rod and along the proximal-distal axis. ### Claim 26 (depends on 17) The instrument of claim 17, wherein the separation of the first and second ramps, while maintaining the initial angle therebetween substantially constant, operates to provide parallel distraction of adjacent bodies when the insertion instrument is positioned within an interbody cavity. ### Claim 27 (depends on 17) The instrument of claim 17, wherein the instrument is configured to receive a compressive force, imparted by vertebral bodies adjacent to the intervertebral space, on the first and second ramps, thereby avoiding loading the implant with the compressive force during insertion of the instrument into the intervertebral space. ### Claim 28 (depends on 27) The instrument of claim 27, wherein the instrument operates to discontinue receiving the compressive force imparted by the vertebral bodies once the implant insertion is complete, thereby transferring the compressive force to the implant. ### Claim 29 (depends on 17) A method for inserting an implant into an intervertebral cavity between adjacent vertebral bodies using the instrument of claim 17, comprising the steps of: sliding the first and second wedges of the instrument relative to one another along the sliding planes thereof to adjust an initial height between the inner surfaces of the respective first and second ramps. ### Claim 30 (depends on 29) The method of claim 29, further comprising determining that the initial height is sufficient to exceed a height of the implant such that no portion of the implant extends to or beyond the inner surfaces of the respective first and second ramps. ### Claim 31 (depends on 30) The method of claim 30, further comprising: coupling the implant directly or indirectly to the first and second wedges; simultaneously sliding the first and second wedges, and the implant, proximally, away from the distal ends of the first and second ramps, such that the vertebral contact surfaces of the respective first and second ramps advance toward one another while holding the initial angle therebetween substantially constant; and inserting the distal ends of the first and second ramps into the intervertebral space. ### Claim 32 (depends on 31) The method of claim 31, further comprising: simultaneously sliding the first and second wedges, and the implant, distally toward the distal ends of the first and second ramps, such that the vertebral contact surfaces of the respective first and second ramps separate from one another while holding the initial angle therebetween substantially constant; and continuing the sliding such that the vertebral contact surfaces of the respective first and second ramps distract the respective vertebral bodies sufficiently to receive the implant into the intervertebral space without compressively loading the implant. ### Claim 33 (depends on 32) The method of claim 32, further comprising simultaneously sliding the first and second wedges, and the implant, distally toward the distal ends of the first and second ramps, such that the implant is received into the intervertebral space without compressively loading the implant. ### Claim 34 (depends on 33) The method of claim 33, further comprising disengaging the implant from the first and second wedges. ### Claim 35 (depends on 34) The method of claim 34, further comprising simultaneously sliding the first and second wedges, without the implant, proximally, away from the distal ends of the first and second ramps, such that the vertebral contact surfaces of the respective first and second ramps advance toward one another while holding the initial angle therebetween substantially constant; and continuing the sliding such that the vertebral contact surfaces of the respective first and second ramps permit the vertebral bodies to compressively load the implant. ### Claim 36 (depends on 35) The method of claim 35, further comprising withdrawing the distal ends of the first and second ramps from the intervertebral space.