`__________________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`__________________
`
`MEDTRONIC, INC.
`Petitioner
`
`v.
`
`NUVASIVE, INC.
`Patent Owner
`
`
`
`Patent Number: 8,361,156 B2
`Issue Date: January 29, 2013
`
`
`
`Case IPR2013-00506
`
`______________________________________________________
`
`
`
`DECLARATION OF HANSEN A. YUAN, M.D.
`
`
`
`Mail Stop “PATENT BOARD”
`Patent Trial and Appeal Board
`U.S. Patent and Trademark Office
`P.O. Box 1450
`Alexandria, VA 22313-1450
`
`
`
`1
`
`NUVASIVE 2020
`Medtronic, Inc. v. NuVasive, Inc.
`IPR2013-00506
`
`
`
`I.
`
`INTRODUCTION AND SCOPE OF WORK
`
`1.
`
`My name is Hansen A. Yuan, M.D. I have been retained by Patent Owner
`
`NuVasive, Inc. (“NuVasive” or “Patent Owner”) in this Inter Partes Review (“IPR”) as an
`
`independent expert in the relevant art.
`
`2.
`
`I have been asked to provide my opinions and analysis regarding the prior art
`
`identified by Petitioner Medtronic, Inc. (“Medtronic” or “Petitioner”) and its expert Richard
`
`Hynes, and on which the Patent Trial and Appeal Board (“PTAB”) has instituted this IPR
`
`related to U.S. Patent No. 8,361,156 (“the ’156 patent”), which is assigned to NuVasive. I
`
`have been asked to consider what one of skill in the art at the time of the filing of the
`
`application that matured as the ’156 patent would have understood from the ’156 patent,
`
`including the scientific and technical knowledge related to the ’156 patent. I have also been
`
`asked to consider whether the references relied on by the PTAB to institute this IPR
`
`disclose or suggest the features claimed by the ’156 patent. My independent analysis is set
`
`forth below.
`
`3.
`
`My opinions and analysis are guided by my understanding and experience as
`
`a person of ordinary skill in the art at the time of the filing of the application that matured as
`
`the ’156 patent on or about March 29, 2004, the priority date for the ’156 patent.
`
`II.
`
`4.
`
`SUMMARY OF OPINIONS
`
`Based on my experience and expertise, discussed below, and my review of
`
`the prior art on which the PTAB instituted IPR for the ’156 patent, it is my opinion that the
`
`
`
`1
`
`2
`
`
`
`cited references would not render Claims 1-14, 19, 20, and 23-27 of the ’156 patent
`
`obvious. In addition, Petitioner did not present an articulated reason with a rational basis for
`
`combining or modifying the primary references on which this IPR was instituted so as to
`
`provide all elements of the invention claimed by the ’156 patent.
`
`III.
`
`BACKGROUND
`
`5.
`
`I am an orthopaedic surgeon board certified by the American Board of
`
`Orthopaedic Surgery and fellowship trained in the treatment of Low Back and Cervical Pain,
`
`including in the use of surgery to treat such conditions. I received my medical degree from
`
`the University of Michigan Medical School Ann Arbor in 1969. I performed my orthopaedic
`
`surgery residency at the State University of New York (“SUNY”) in Syracuse, New York from
`
`1971-1974. I did my fellowship training with Professor Leon Wiltse at Long Beach Memorial
`
`Hospital and Rancho Los Amigos, affiliated with USC and UCLA. I have been a practicing
`
`spine surgeon since 1974.
`
`6.
`
`I have performed more than 9,000 spine surgeries in my career, including
`
`anterior, posterior and lateral interbody procedures. In the cervical spine, such procedures
`
`include discectomies and fusions. In the thoracolumbar spine, I have performed Anterior
`
`Lumbar Interbody Fusions (“ALIF”), Posterior Lumbar Interbody Fusions (“PLIF”),
`
`Transforaminal Lumbar Interbody Fusions (“TLIF”), eXtreme Lateral Interbody Fusions
`
`(“XLIF”), lateral open procedures, posterior open procedures, and laproscopic fusions and
`
`discectomy procedures, among others.
`
`
`
`2
`
`3
`
`
`
`7.
`
`I have held numerous academic appointments at SUNY, including serving as
`
`Professor and Chairman of Othopaedic Surgery from 1987-1989. I was also Professor of
`
`Orthopaedic and Neurological Surgery at SUNY from 1990-2007. Since March 2007, I have
`
`served as Professor Emeritus in the Department of Orthopaedic and Neurological Surgery
`
`at SUNY. I have trained more than 200 spine fellows in the spine fellowship program at
`
`SUNY (25 of those being surgeons practicing in the United States and more than 180
`
`additional spine fellows who are practicing worldwide). In addition, I have been invited
`
`numerous times to serve at visiting professor or present Grand Rounds at various academic
`
`institutions throughout the world, all related to orthopaedic surgery and specifically spine
`
`surgery. Some of the more recent examples include lecturing regarding (1) Kyphoplasty for
`
`Osteoporotic Compression Fractures at the Hospital for Special Surgery in New York, New
`
`York (2003), which is widely considered to have one of the finest orthopaedics departments
`
`in the nation; (2) Nucleus Replacement surgery at the Texas Back Institute; and (3)
`
`presenting Grand Rounds regarding the future of degenerative disc disease at Yale
`
`University in New Haven Connecticut, among many others.
`
`8.
`
`I have received numerous honors and awards recognizing my work in the
`
`field of orthopaedic spine surgery, including among many others, the Best Clinical Paper
`
`Award (2008) and the Award for Best Overall Paper (2007) from the Spine Arthroplasty
`
`Society; the David Selby Award from the North American Spine Society (“NASS”) which
`
`recognized my contributions to the art and science of spinal disorder management through
`
`
`
`3
`
`4
`
`
`
`service to NASS, the Volvo Award for Low Back Research ("Vertebral burst fractures: An
`
`experimental Disc in Flexion-Compression and in Pure Compression") and the Leon Wiltse
`
`Award from NASS which recognized my leadership and clinical research in spine care. I am
`
`a past president of NASS and of the Spine Arthroplasty Society. I have also been granted a
`
`Lifetime Honorary Professorship by the Chinese Institute for Space Science and Medical
`
`Engineering, among other awards.
`
`9.
`
`I have been actively involved in research related to spine surgery and spine
`
`care for most of the last three decades. I have presented more than 100 times on topics
`
`related to spine treatments, spine surgery or the use of spinal implants for the treatment of
`
`spine disease and disorders. I am listed as an author or co-author on more than 90 peer
`
`reviewed articles related to treatment, surgery or the use of implants in the spine. I have
`
`also authored or co-authored more than 15 book chapters related to treatment of spinal
`
`disorders, including spine surgery techniques. I have served on numerous editorial boards
`
`for peer-reviewed spine journals, including Complications in Orthopaedics, Journal of Spine
`
`Disorders, Journal of Spine, Journal of Spinal Research, Spine Letter, The Spine Journal,
`
`Orthopaedics Today, and The Spine Arthroplasty Society Online Journal, among others. I
`
`have been the Editor in Chief of the ISAAS online journal for the last six years. Further, I
`
`have been involved in the design and testing of several spinal implants and medical devices
`
`for use in spine surgery. Several of those designs have resulted in issued patents on which
`
`I am listed as a named inventor.
`
`
`
`4
`
`5
`
`
`
`10.
`
`A copy of my curriculum vitae is attached as Exhibit 2021 to this declaration.
`
`I am not, and never was, an employee or clinical research consultant for NuVasive, Inc. I
`
`have been, and am still, on boards for a number of organizations. At one time in the past, I
`
`was on NuVasive’s Board, but that position ended years ago. I receive no royalty income
`
`from NuVasive, but I do receive royalty income from Medtronic (and other spine companies)
`
`stemming from my earlier innovations provided to Medtronic (and the other spinal
`
`companies). In addition, I have stock purchase options in a number of spinal companies,
`
`including NuVasive, which I have not exercised. I have been engaged in the present matter
`
`to provide my independent analysis of the issues raised by the declaration of Dr. Hynes and
`
`the proposed prior art combinations set forth in Medtronic’s Petition for inter partes review of
`
`the ’156 patent. I received no compensation for this declaration beyond my normal hourly
`
`compensation based on my time actually spent studying the matter, and I will not receive
`
`any added compensation based on the outcome of the above-mentioned inter partes review
`
`of the ’156 patent.
`
`IV.
`
`BASIS FOR OPINIONS
`
`11. My opinions and analysis set forth in this declaration are based on my
`
`education, training, and experience as summarized above and detailed in my curriculum
`
`vitae, as well as my review of the ’156 patent, and the prior art on which the PTAB instituted
`
`IPR.
`
`
`
`5
`
`6
`
`
`
`12.
`
`In forming my opinions and preparing this declaration, I reviewed the ’156
`
`patent, including the claims, specification, figures, and file history. I have also reviewed the
`
`file history for U.S. Patent Application No. 11/093,409 (“the ’409 application”), which is the
`
`application to which the ’156 patent claims priority.
`
`13. Regarding the prior art at issue in this IPR, I specifically reviewed Synthes
`
`Vertebral Spacer-PR (“SVS-PR”) brochure which is alleged to have been published in 2002,
`
`two brochures describing the Medtronic Telamon Verte-Stack Vertebral Body Spacer
`
`(“collectively referred to as “Telamon”) which are alleged to have been published in 2003,
`
`U.S. Published Application No. 2003/0028249 to Baccelli (“Baccelli”), and U.S. Patent No.
`
`5,860,973 to Michelson (“Michelson ’973”). I have also reviewed additional documents
`
`related to SVS-PR and Telamon, including the surgical technique guides and recommended
`
`use documents published by Synthes and Medtronic, respectively. Additionally, I have
`
`reviewed other publications cited by Medtronic’s Petition or the accompanying Declaration
`
`of Dr. Richard Hynes, such as U.S. Published Application No. 2002/0165550 to Frey
`
`(“Frey”), U.S. Published Application No. 2003/0023306 to Liu (“Liu”), U.S. Patent No.
`
`6,241,770 to Michelson (“Michelson ’770”), and the journal article by Zhou et al.,
`
`Geometrical Dimensions of the Lower Lumbar Vertebrae, 9 EUR. SPINE J. 242, 244 (2000)
`
`(“Zhou”). I was informed that NuVasive will submit additional exhibits, such as Moro et al.,
`
`An anatomic study of the lumbar plexus with respect to retroperitoneal endoscopic surgery,
`
`Spine Vol. 28 (2003), pp. 423-428 (Exhibit 2019), and Medtronic, Boomerang Verte-Stack
`
`
`
`6
`
`7
`
`
`
`PEEK Vertebral Body Spacer (2003) (Exhibit 2012), and Sythes Spine, Vertebral Spacer-
`
`PR, Vertebral body replacement device intend for use in the thoracolumbar spine (2002)
`
`(Exhibit 2011), and the other documents cited below, all of which I have also considered.
`
`Finally, my analysis is based on having personally used both the SVS-PR and Telamon
`
`devices in surgery throughout the years.
`
`14.
`
`I have also considered Medtronic’s Petition for IPR regarding the ’156, the
`
`Declaration of Dr. Richard Hynes in support of Medtronic’s Petition for IPR in this matter,
`
`and the PTAB Decision dated February 13, 2014 that instituted IPR in this matter. I have
`
`also reviewed the deposition transcript of Dr. Hynes taken in this matter in forming my
`
`opinions.
`
`V.
`
`THE LAW OF OBVIOUSNESS
`
`15.
`
`In preparing my analysis, I have applied the legal standards described below,
`
`which were provided to me by counsel for NuVasive.
`
`16.
`
`I understand that Dr. Hynes contends the asserted claims of the patents-in-
`
`suit patent are not valid because they are obvious in view of certain prior art references.
`
`17.
`
`It is my understanding that assessing the validity of a U.S. Patent based on a
`
`prior art analysis requires two essential steps. First, in an IPR proceeding, one must
`
`construe the terms of the patent claims to understand what meaning they would have to one
`
`of ordinary skill in the art under the broadest reasonable interpretation that is consistent with
`
`the specification. For purposes of my analysis, I have considered Medtronic’s proposed
`
`
`
`7
`
`8
`
`
`
`constructions (Petition at Section III.C), and find that even under Medtronic’s proposed
`
`constructions, the proposed ground for rejection are lacking and the ‘156 patent claims are
`
`not obvious.
`
`18.
`
`Second, after the claim terms have been construed, one may then assess
`
`validity by comparing a patent claim to the “prior art.” For purposes of my independent
`
`analysis herein, I have assumed that all of the references cited in the grounds for rejection
`
`in the PTAB Decision dated February 13, 2014 (SVS-PR, Telamon, Baccelli, and Michelson
`
`’973) to be prior art. See February 13, 2014 PTAB Decision at pp. 19-20.
`
`19.
`
`Even if each of SVS-PR, Telamon, Baccelli, and Michelson ’973 is considered
`
`to be a prior art publication, I find that the proposed ground for rejection are lacking and the
`
`‘156 patent claims are not rendered obvious by the proposed combinations cited in the
`
`grounds for rejection in the PTAB Decision dated February 13, 2014.
`
`20.
`
`I understand that the teaching of the prior art is viewed through the eyes of a
`
`person of ordinary skill in the art at the time the invention was made. To assess the level of
`
`ordinary skill in the art, I understand one can consider the types of problems encountered in
`
`the art, the prior solutions to those problems found in prior art references, the rapidity with
`
`which innovations are made, the sophistication of the technology, and the level of education
`
`of active workers in the field. My opinion as to what constitutes a relevant person of
`
`ordinary skill in the art is set forth below.
`
`21.
`
`I understand that Dr. Hynes contends the challenged claims are invalid as
`
`
`
`8
`
`9
`
`
`
`“obvious.” A patent claim is invalid as obvious only if the subject matter as a whole of the
`
`claimed invention would have been obvious to a person of ordinary skill in the field at the
`
`time the invention was made. This means that even if all of the requirements of the claim
`
`cannot be found in a single prior art reference that would “anticipate” the claim, a person of
`
`ordinary skill in the field who knew about all this prior art would have come up with the
`
`claimed invention.
`
`22. However, I understand that a patent claim composed of several elements is
`
`not proved obvious merely by demonstrating that each of its elements was independently
`
`known in the prior art. In evaluating whether such a claim would have been obvious, I
`
`considered whether Medtronic’s Petition or the Declaration of Dr. Hynes presented an
`
`articulated reason with a rational basis that would have prompted a person of ordinary skill
`
`in the field to combine the elements or concepts from the prior art in the same way as in the
`
`claimed invention. I understand there is no single way to define the line between true
`
`inventiveness on one hand (which is patentable) and the application of common sense and
`
`ordinary skill to solve a problem on the other hand (which is not patentable). For example,
`
`market forces or other design incentives may be what produced a change, rather than true
`
`inventiveness. It is my understanding that the decision-maker may consider whether the
`
`change was merely the predictable result of using prior art elements according to their
`
`known functions, or whether it was the result of true inventiveness. And, the decision-maker
`
`may also consider whether there is some teaching or suggestion in the prior art to make the
`
`
`
`9
`
`10
`
`
`
`modification or combination of elements claimed in the patents-in-suit. Also, the decision-
`
`maker may consider whether the innovation applies a known technique that had been used
`
`to improve a similar device or method in a similar way. The decision-maker may also
`
`consider whether the claimed invention would have been obvious to try, meaning that the
`
`claimed innovation was one of a relatively small number of possible approaches to the
`
`problem with a reasonable expectation of success by those skilled in the art. However, I
`
`understand that the decision-maker must be careful not to determine obviousness using the
`
`benefit of hindsight and that many true inventions might seem obvious after the fact. I
`
`understand that the decision-maker should consider obviousness from the position of a
`
`person of ordinary skill in the field at the time the claimed invention was made and that the
`
`decision-maker should not consider what is known today or what is learned from the
`
`teaching of the patent.
`
`23.
`
`I understand the ultimate conclusion of whether a claim is obvious should be
`
`based upon my determination of several factual decisions. First, the decision-maker must
`
`assess the level of ordinary skill in the field that someone would have had at the time the
`
`claimed invention was made. Second, the decision-maker must decide the scope and
`
`content of the prior art. Third, the decision-maker must decide what difference, if any,
`
`existed between the claimed invention and the prior art.
`
`24.
`
`It is my understanding that the existence of one or more objective factors of
`
`non- obviousness can rebut a showing of obviousness based on prior art. These objective
`
`
`
`10
`
`11
`
`
`
`factors include:
`
`(1) commercial success of a product due to the merits of the claimed invention;
`
`(2) a long felt need for the solution provided by the claimed invention;
`
`(3) unsuccessful attempts by others to find the solution provided by the claimed
`invention;
`
`(4) copying of the claimed invention by others;
`
`(5) unexpected and superior results from the claimed invention;
`
`(6) acceptance by others of the claimed invention as shown by praise from others in
`the field or from the licensing of the claimed invention;
`
`(7) teaching away from the conventional wisdom in the art at the time of the
`invention
`
`(8) other evidence tending to show nonobviousness;
`
`(9) independent invention of the claimed invention by others before or at about the
`same time as the named inventor thought of it; and
`
`(10) other evidence tending to show obviousness.
`
`25.
`
`It is my understanding that, in order to establish a secondary consideration of
`
`non- obviousness, NuVasive must show a nexus between that secondary consideration and
`
`the claimed invention.
`
`VI.
`
`THE FIELD OF SPINAL FUSION IMPLANTS
`
`A.
`
`The Human Spine
`
`26.
`
`The human spine, or vertebral column, consists of 26 bones, including 24
`
`vertebrae, the sacrum, and the coccyx. The vertebrae provide a column of support, bearing
`
`the weight of the head, neck, and trunk, ultimately transferring that weight to the skeleton of
`
`
`
`11
`
`12
`
`
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`the lower limbs. The vertebral column also protects the spinal cord. Anterior to the
`
`vertebral column lie the great vessels, the aorta and vena cava. The spinal cord and great
`
`vessels are shown in the figure below on the left. In addition, the lumbar portion of the
`
`spine is flanked on each side by a highly innervated muscle called the psoas. Sensitive
`
`nerve roots and the lumbar plexus run through the psoas muscle. Historically, ordinary
`
`surgeons before 2004 avoided approaching the lumbar spine from the lateral, transpsoas
`
`approach because of the fear of neurologic injury associated with penetrating the psoas
`
`muscle. See Moro, pp. 423, 428 (expressing the conventional wisdom at the time that
`
`ordinary spine surgeons “have not felt comfortable with dissecting the psoas because of the
`
`presence of the lumbar plexus”).
`
`
`
`
`
`12
`
`13
`
`
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`27.
`
`As depicted above in the figure on the right, the vertebral column is divided
`
`into regions. The cervical spine begins at the skull and consists of seven vertebrae
`
`constituting the neck and extending inferiorly to the trunk. Below the cervical region lie the
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`twelve thoracic vertebrae that form the mid-back region and articulate with one or more
`
`pairs of ribs. Five lumbar vertebrae form the lower back, with the fifth articulating with the
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`sacrum, which in turn articulates with the coccyx. The cervical, thoracic, and lumbar regions
`
`consist of individual vertebrae.
`
`28.
`
`As depicted in the figure below, a vertebra is identified by various parts,
`
`including (1) a vertebral body, (2) a vertebral arch, (3) the articular processes, (4) the
`
`spinous process, and (5) the transverse process. The body of a vertebra transfers weight
`
`along the axis of the vertebral column and is separated from neighboring vertebrae by
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`intervertebral discs (“Disc”). A Disc is composed of fibrocartilage, articular cartilage,
`
`mucinous material (disc material), and collagen ligament material. A Disc attaches to the
`
`bony endplate of each adjacent vertebrae. Discs serve to (1) absorb vertical pressure
`
`placed on the body, (2) provide stability and support at the vertebral adjacent motion
`
`segments, (3) provide space that protects the exiting nerve routes and the central spinal
`
`column, and (4) restrict the range of motion between two adjacent vertebral bodies, among
`
`other things. Those of skill in the art often divide the spine into two hemispheres: (1) the
`
`anterior spinal column (which consists of the vertebral body and the discs), and (2) the
`
`
`
`13
`
`14
`
`
`
`posterior spinal column (which consists of the vertebral arch, the articular processes, the
`
`spinous process, the transverse process, and the spinal cord).
`
`
`
`
`
`29.
`
`The portion of the vertebral body adjacent to the Disc is covered by a thin
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`layer of dense, subchondral bone known as the vertebral endplate. The endplate has a
`
`central region of condensed, cancellous bone. Toward the vertebral periphery lies a thin,
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`strong layer of dense bone known as the apophyseal ring that serves as the attachment site
`
`for the annulus fibrosus of the Disc.
`
`30.
`
`The average dimensions of the human vertebrae have been described in
`
`literature, including the Zhou reference cited by Dr. Hynes. See Ex. 1113; Hynes Decl., ¶
`
`78. There are other published studies that also attempt to provide the average sizes of
`
`vertebrae at various levels in humans.
`
`
`
`14
`
`15
`
`
`
`B.
`
`Fusion Procedures
`
`31.
`
`Fusion is the surgically induced union or healing of bone. The goal of
`
`interbody fusion, a type of arthrodesis, is to induce bone growth between two vertebrae into
`
`a single bony bridge using surgery. The procedure is designed to restore Disc height and
`
`immobilize the vertebrae to alleviate the pain caused by motion. Fusion also promotes
`
`stability, and, in certain cases, restores proper spinal lordosis. Interbody fusion occurs in
`
`the anterior spinal column.
`
`32. Conditions for which spinal fusion surgeries are performed include
`
`degenerative disc disease, spinal fracture secondary to a traumatic injury, scoliosis
`
`(abnormal lateral curvature of the spine), spondylolisthesis (anterior displacement of a
`
`vertebra), spondylosis (osteoarthritis of the vertebral joints), spinal disc herniation, and other
`
`spinal instability caused by degeneration of the vertebrae.
`
`33. Most commonly, spinal fusion is used to treat degenerative disc disease,
`
`which refers to the gradual deterioration of the intervertebral discs between the vertebrae in
`
`the spine. As the body ages, the annulus fibrosus may wear and eventually crack, while the
`
`inner portion of the intervertebral discs may lose water content, causing the disc to become
`
`thin and stiff. As this occurs, the shock absorption properties of the discs weaken, and the
`
`nerve openings along the sides of the spine narrow, placing pressure on the nerves which
`
`may cause pain, which is often debilitating. Abnormal motion between the vertebrae also
`
`results, causing pain.
`
`
`
`15
`
`16
`
`
`
`34. Historically, the more common approaches to the spine were either an
`
`anterior or posterior surgical approach to the intervertebral disc space. These approaches
`
`include ALIF, PLIF, and TLIF. These approaches pose significant risks to either the great
`
`vessels, running anterior to the vertebral column, or the spinal cord, running posterior to the
`
`vertebral bodies. In the ALIF procedure, for example, the surgeon performing the operation
`
`prepares the disc space and implants the spinal device from an anterior approach or via the
`
`patient’s front through the abdomen. This approach risks damage to aorta and vena cava
`
`that lie anterior to the spine and must be retracted, often requiring a second access
`
`surgeon. In the PLIF and TLIF procedures, the surgeon performing the operation prepares
`
`the disc space and implants a spinal device into holes drilled across the inner disc space
`
`between the vertebral bodies from a posterior approach or via the patient’s back. This
`
`approach risks damage to the spinal cord and spinal nerves, as well as damage to the
`
`posterior spinal supporting musculature. (’973 patent at 1:21-23; 3:56-60). Damaging the
`
`spinal cord and the nerves lying in the vicinity can result in loss of sensation, retrograde
`
`ejaculation, and even paralysis in the most extreme cases.
`
`35.
`
`The anatomical constraints imposed by anterior and posterior approaches to
`
`the intervertebral space limit the efficacy of the interbody implants that can be used,
`
`primarily by limiting the size of the implants to the dimensions of the vertebrae relative to the
`
`direction in which the implants were inserted. (See e.g., Michelson ’973 patent at 1:66-2:2).
`
`The maximum possible length for an implant that is inserted from either the front or the back
`
`
`
`16
`
`17
`
`
`
`of the patient is limited to the depth of the vertebrae, measured from the anterior to posterior
`
`end of the vertebrae. (See e.g., Michelson ’973 patent at 2:1-10).
`
`C.
`
`Development of Spinal Implants
`
`36. When I started my career as a spine surgeon in 1974, artificial fusion implants
`
`were virtually non-existent. Fusion procedures were primarily attempted using a patient’s
`
`own bone tissue (autograft). There were several complications associated with the use of
`
`autograft. For example, a patient’s own tissue (bone) would have to be harvested from a
`
`second surgical site, usually the iliac crest. This created a second incision in the patient,
`
`increasing the morbidity associated with fusion procedures. This was complicated by the
`
`fact that patients undergoing fusion procedures were already in a debilitated state due to
`
`age or disease or both.
`
`37.
`
`Subsequently, surgeons started using cadaveric bone (allograft) for fusion
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`procedures. This presented at different set of complications. First, there was a moral
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`dilemma associated with using cadaveric bone. Second, there was a concern that the
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`cadaveric bone would carry disease that could be transmitted to the recipient. This concern
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`increased in the late 1980s and early 1990s with the onset of the HIV and hepatitis
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`epidemics.
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`38.
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`By the early-1990s, surgeons were looking to artificial materials for use as
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`fusion implants. These implants fell under the governance of the Food and Drug
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`Administration (“FDA”) because they were considered implantable medical devices. Thus,
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`17
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`18
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`for artificial implants to be approved for use in fusion surgeries, they needed to go through
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`an FDA approval process and be cleared for use in surgery. This was often a long and
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`involved process.
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`39.
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`Today, artificial implants for use in fusion procedures continue to be regulated
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`by the FDA. Modern implants are designed for specific uses and for specific approaches to
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`the spine to ensure clinical safety, effectiveness, and repeatability by the majority of the
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`surgeon population. As but one example, the Telamon implant referenced in the Telamon
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`literature cited by Petitioner and Dr. Hynes was designed to be used as a posterior or PLIF
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`implant. That is, the implant was designed to be inserted from the posterior (or back) side
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`of the patient in a posterior-anterior direction. This is confirmed by the surgical technique
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`guide for the Telamon that shows the implant being inserted in a direct posterior-anterior
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`direction via a PLIF procedure. See Ex. 1108. Further, the sizes available for the Telamon
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`implant reflect that it was intended for insertion in a direct posterior-anterior direction (along
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`a sagittal plane and perpendicular to a coronal plane). Indeed, my personal use of the
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`Telamon implant was exclusively from a posterior approach. I inserted the Telamon implant
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`only in a posterior-anterior direction. Moreover, because I was at a teaching hospital and
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`had many fellows who were learning how to perform spine fusion surgeries, my colleagues
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`and I were careful to instruct our fellows in the proper use of these types of PLIF implants.
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`Surgeons today receive extensive training using spinal implant and access equipment to
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`ensure safe, effective, and repeatable results.
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`19
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`40. Most modern spinal fusion implants are designed by surgeons, often working
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`with biomedical engineers, to create new and better spine products. The process if often
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`iterative and time consuming, i.e., where an implant is designed, tested, and then modified
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`to ensure the highest quality product for use in human patients. I cannot emphasize this
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`point enough because in my experience designing and using interbody fusion implants,
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`small changes in design (especially features such as the implant dimensions and
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`radiopaque marker structure/positioning) can have significant impacts on the functionality of
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`the implant as used by the surgeon and the clinical benefits of the implant to the patient
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`population. A small increase in the size of the implant, i.e., a few millimeters difference or a
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`few degrees difference in lordosis, can prevent or otherwise hinder the original intended use
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`and can mean the difference between an implant that alleviates pain, and one that causes
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`significant additional problems for the patient.
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`41.
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`Spinal Interbody fusion implants have to be designed to support the heavy
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`loads placed on the spine, to help align the spine and alleviate pain cause by misalignment,
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`to prevent ejection from the disc space after insertion, and to promote fusion of the two
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`adjacent vertebrae. While it is generally true that interbody fusion implant designers try to
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`design implants with large surface areas, i.e., large footprints, the size of such implants
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`remain limited by the above-described anatomical limitations and the original intended use
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`(for example, the original intended use of Telamon as a PLIF implant). The large surface
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`area of the implant can provide greater structural support and restoring proper spacing
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`19
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`20
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`between the vertebrae. It is critically important that interbody fusion implants can be
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`inserted along the intended insertion path, can be positioned in the disc space, support the
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`intended load, stay in place after insertion, align the spine, and allow fusion of the vertebrae.
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`If an interbody fusion implant fails in one of these areas when used in a particular
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`procedure, it will not suitable for that procedure.
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`D.
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`Materials Science for Modern Implants
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`42.
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`As stated above, the first interbody fusion implants were made of a patient’s
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`own bone or cadaveric bone. Beside the complications discussed above, bone also made it
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`challenging for surgeons to determine if fusion had actually occurred post-operatively. To
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`determine fusion, most surgeons have traditionally used and continue to use post-operative
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`x-ray. Generally, x-ray uses radiation to determine the difference in density between
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`different types of tissue in the body. For example, empty space in the body or soft tissue
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`(such as spinal discs) has little density, will absorb little radiation, and will show up on x-ray
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`films as darker areas when using standard radiographic techniques. Soft tissue is generally
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`referred to as “radiolucent.” In contrast, bone, which has a higher density, will absorb more
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`radiation, and will show up on x-ray films as white areas when using standard radiographic
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`techniques. Bone is generally referred to as “radiopaque.” Thus, using bone for an
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`interbody fusion implant would show up white on post-operative x-rays, and surgeon would
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`have to differentiate between the white of the implant itself and the white of the fusion of the
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`two adjacent vertebrae.
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`43. When the first artificial implants were developed, most were make from
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`titanium or other biologically compatible metals. See e.g., Michelson ’973 at Col. 5:65-6:5.
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`These