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SUMMARY OF SAFETY & EFFECTIVENESS DATA (SSED)I. GENERAL INFORMATIONDevice Generic Name:Prosthesis, Spinous Process Spacer/PlateDevice Trade Name:Superion InterSpinous Spacer (ISS)Device Product Code:NQOApplicant’s Name and Address:VertiFlex , Incorporated1351 Calle Avanzado, Suite 100San Clemente, CA 92673Date(s) of Panel Recommendation: February 20, 2015Premarket Approval Application(PMA) Number:P140004Date of FDA Notice of Approval:May 20, 2015II. INDICATIONS FOR USEThe Superion InterSpinous Spacer (ISS) is indicated to treat skeletally mature patients suffering frompain, numbness, and/or cramping in the legs (neurogenic intermittent claudication) secondary to adiagnosis of moderate degenerative lumbar spinal stenosis, with or without Grade 1 spondylolisthesis,confirmed by X-ray, MRI and/or CT evidence of thickened ligamentum flavum, narrowed lateralrecess, and/or central canal or foraminal narrowing. The Superion ISS is indicated for those patientswith impaired physical function who experience relief in flexion from symptoms of leg/buttock/groinpain, numbness, and/or cramping, with or without back pain, and who have undergone at least 6months of non-operative treatment. The Superion ISS may be implanted at one or two adjacentlumbar levels in patients in whom treatment is indicated at no more than two levels, from L1 to L5.For this intended use, moderate degenerative lumbar spinal stenosis was defined as follows: 25% to 50% reduction in the central canal and/or nerve root canal (subarticular, neuroforaminal)compared to the adjacent levels on radiographic studies, with radiographic confirmation of any oneof the following:o Evidence of thecal sac and/or cauda equina compressiono Evidence of nerve root impingement (displacement or compression) by either osseous or nonosseous elementso Evidence of hypertrophic facets with canal encroachment AND associated with the following clinical signs:o Presents with moderately impaired Physical Function (PF) defined as a score of 2.0 of theZurich Claudication Questionnaire (ZCQ)o Ability to sit for 50 minutes without pain and to walk 50 feet or more.PMA P140004: FDA Summary of Safety and Effectiveness DataPage 1 of 61

III. CONTRAINDICATIONSThe Superion ISS is contraindicated in patients with: an allergy to titanium or titanium alloy;spinal anatomy or disease that would prevent implantation of the device or cause the device tobe unstable in situ, such as:o instability of the lumbar spine, e.g., isthmic spondylolisthesis or degenerativespondylolisthesis greater than grade 1 (on a scale of 1 to 4);o an ankylosed segment at the affected level(s);o fracture of the spinous process, pars interarticularis, or laminae (unilateral or bilateral);o scoliosis (Cobb angle 10 degrees);Cauda equina syndrome defined as neural compression causing neurogenic bladder or boweldysfunction;diagnosis of severe osteoporosis, defined as bone mineral density (from DEXA scan orequivalent method) in the spine or hip that is more than 2.5 S.D. below the mean of adultnormals;active systemic infection, or infection localized to the site of implantation;prior fusion or decompression procedure at the index level;morbid obesity defined as a body mass index (BMI) greater than 40.IV. WARNINGS AND PRECAUTIONSThe warnings and precautions can be found in the Superion ISS labeling.V. DEVICE DESCRIPTIONThe Superion ISS is a one-piece implant that requires no assembly in situ. It consists of an implantbody, within which resides the actuation mechanism, and two Cam Lobes, or “wings” which – whendeployed – rotate away from the axis of the implant body to encompass the lateral aspects of thesuperior and inferior spinous processes (see Figure 1).PMA P140004: FDA Summary of Safety and Effectiveness DataPage 2 of 61

Figure 1: Superion device in spine modelThe Superion ISS is composed entirely of titanium alloy (Ti6Al-4V ELI conforming to ASTM F136)The Superion ISS is intended to be implanted via minimally-invasive surgical methods using a set ofproprietary accessory instruments provided by VertiFlex expressly for use with the Superion ISSdevice. Together, the implants and manual instruments form a complete system for implantation of theSuperion ISS.To accommodate variations in patient anatomy, Superion ISS implants are available in five (5) sizes,ranging from 8mm to 16mm in 2mm increments, each of which is color-coded and laser-etched toindicate implant size. The size selection determines the amount of “spacing” between the two adjacentspinous processes. Implant size is determined by the distance between the bottom of the “saddle” ofeach of the Cam Lobes, which represents the point at which the adjacent spinous processes would restwithin a deployed implant.VI. ALTERNATIVE PRACTICES AND PROCEDURESNon-surgical alternatives include non-steroidal anti-inflammatory drugs (NSAIDs), analgesics, oraland epidural steroids, rest, exercise, physical therapy, and bracing. Surgical alternatives to theSuperion ISS vary, depending upon the severity of the stenosis, the contribution of back pain, and thepresence of instability, among other factors, and can include various direct decompressive procedures(e.g. laminectomy, laminotomy, hemilaminotomy, foraminotomy, etc.), other FDA-approvedinterspinous distraction devices, direct decompression with non-fusion posterior stabilization devices,and decompression with posterolateral fusion with pedicle screw instrumentation. Each alternative hasits own advantages and disadvantages. A patient should discuss these alternatives with his or herphysician to select the option that best meets their clinical condition, lifestyle and expectations.PMA P140004: FDA Summary of Safety and Effectiveness DataPage 3 of 61

VII. MARKETING HISTORYThe Superion ISS has been marketed outside of the United States since 2007, and has not beenwithdrawn from marketing for any reason. The Superion ISS is marketed in: Germany, Israel, Italy,Mexico, Netherlands, South Africa, Spain and the United Kingdom.VIII. POTENTIAL ADVERSE EFFECTS OF THE DEVICE ON HEALTHBelow is a list of potential adverse effects (e.g., complications) associated with use of the Superion ISS. This listing was derived from results of the Superion ISS clinical trial conducted underInvestigational Device Exemption (IDE) #G070118, approved device labeling for other interspinousdevices, and published clinical literature. It includes (1) those adverse effects potentially associatedwith any surgical procedure; (2) those potentially associated with lumbar spine surgery; (3) thosepotentially associated with lumbar spinal implants, and in particular with interspinous processimplants; and (4) those potentially associated with the Superion ISS in particular. In some instances,additional surgery may be required to correct adverse effects.1. Risks associated with any surgical procedure include: anesthetic medication reactions; bloodloss, blood vessel damage, phlebitis or hematoma; blood transfusion which may causecirculatory collapse, blood incompatibility, kidney damage, hepatitis or infection with HIV;myocardial infarction or circulatory problems; deep vein thrombosis, pulmonary embolism orthrombus formation in other vessels; stroke; fever or infection; pneumonia; injury to muscle,soft tissue or nerves; wound swelling, drainage or delayed healing; discomfort andrehabilitation associated with recovery from surgery; inability to perform certain tasks, such aslifting or exercise; and death.2. Risks associated with lumbar spine surgery include: damage to nerve roots or the spinal cordcausing partial or complete sensory or motor loss (paralysis); loss of bladder and/or bowelfunctions; dural leaks (tears in the tissue surrounding and protecting the spinal cord);instruments used during surgery may break or malfunction which may cause damage to theoperative site or adjacent structures; fracture, damage or remodeling of adjacent anatomy,including bony structures or soft tissues during or after surgery; new or worsened back or legpain; and surgery at the incorrect location or level.3. Risks associated with lumbar spine implants and associated instruments include: sensitivity orallergy to the implant material; failure of the device/procedure to improve symptoms and/orfunction; pain and discomfort associated with the operative site or presence of implants;implant malposition or incorrect orientation; spinous process fracture; production of weardebris which may damage surrounding soft tissues including muscle or nerve; formation of scartissue at implant site; migration or dislodgement of the implant from the original position sothat it becomes ineffective or causes damage to adjacent bone or soft tissues including nerves;loosening, fatigue, deformation, breakage or disassembly of the implant, which may requireanother operation to remove the implant and may require another method treatment.PMA P140004: FDA Summary of Safety and Effectiveness DataPage 4 of 61

4. Risks specifically associated with the Superion ISS include deformation, breakage ordisassembly of the implant, and spinous process fracture.For the specific adverse events that occurred in the clinical study of the Superion ISS, please seeSection X below.IX. SUMMARY OF PRECLINICAL STUDIESA variety of non-clinical tests were conducted to characterize the performance of the Superion ISS.These tests as are listed below and summarized in Table 1 and Table 2:A. Laboratory Studies Static Axial Compression Static Torsion Dynamic Axial Compression Dynamic Torsion Implant Deployment Under Load Static Torsion After Repeated Deployment Under Load Quantification and Characterization of Wear Debris Kinematic and Kinetic Behavior in Human Cadaver Spines Role of Supraspinous Ligament in Biomechanical Stability Effects of Implant on Canal and Foraminal DimensionsB. Additional Studies Sterilization, Shelf-Life and Packaging Biocompatibility MRI CompatibilityA. Laboratory StudiesTestStatic AxialCompressionTable 1: Laboratory Studies on Superion ISSAcceptancePurposeMethodCriteriaTo evaluate theSix (6) samples of the largestMaximumperformance of(16mm) and smallest (8mm)compressive implant were tested in accordancestrength mustthe SuperionwithmethodsspecifiedbyASTMexceed maximumISS under staticF1717expected in vivoaxialspinous processcompressivefailure loadloading, under(320N).1worst-caseconditions.PMA P140004: FDA Summary of Safety and Effectiveness DataResultsMean yield load was 8,900 N (8mm) and 8,100 N (16mm).These results suggestthat the device canresist compressive loadsthat exceed theanticipated physiologicfailure load (320N) inthe lumbar spine.Page 5 of 61

TestStatic TorsionTestingTable 1: Laboratory Studies on Superion ISSAcceptancePurposeMethodCriteriaTo evaluate theSix (6) samples of the largestMaximumperformance of(16mm) and smallest (8mm)torsional strength implant were tested in accordancemust exceedthe SuperionwithmethodsspecifiedbyASTMmaximumISS under staticF1717expected in vivotorsional loading,spinous processunder worst-casefailure loadconditions.(320N).1Dynamic AxialCompressionTo evaluate theperformance of the SuperionISS underdynamic axialcompressiveloading, underworst-caseconditions.Six (6) samples of the largest(16mm) and smallest (8mm)implant were tested in accordancewith methods specified by ASTMF1717Maximumdynamic runoutload to 10 millioncycles mustexceed maximumexpected in vivospinous processfailure load(320N).1DynamicTorsionTo evaluate theperformance of the SuperionISS underdynamictorsional loading,under worst-caseconditions.Six (6) samples of the largest(16mm) and smallest (8mm)implant were tested in accordancewith methods specified by ASTMF1717Maximumdynamic runouttorsion to 10million cyclesmust exceedmaximumexpected in vivospinous processfailure load(320N).1ImplantDeploymentUnder LoadTo evaluate theability of the Superion ISS tobe deployedunder axial loadFive (5) implants were deployedunder constant resisting axial loadsof 250, 300, and 350 N.Implants mustdeploy withoutdamage orfunctional failureunder axial loadexceeding failurestrength of thespinous processes(320N).1PMA P140004: FDA Summary of Safety and Effectiveness DataResultsMean yield torque was 30.6 N-m (8mm) and 15 N-m (16mm).These results suggestthat the device canresist torsional loadsthat exceed theanticipated physiologicfailure load (320N) inthe lumbar spine.Dynamic runout load to10 million cycles forboth 8mm and 16mmimplant sizes was 1,750N. These results suggestthat the device canresist dynamiccompressive loads thatexceed the anticipatedphysiologic failure load(320N) in the lumbarspine.Dynamic runout load to10 million cycles was 2.5 N-m (8mm) and 3 N-m (16mm). Theseresults suggest that thedevice can resistdynamic torsional loadsthat exceed theanticipated physiologicfailure load (320N) inthe lumbar spine.All implants deployedwithout failure underaxial loads of 250, 300,and 350 N. Theseresults suggest that thedevice can adequatelydeploy in the presenceof loads that exceed thestrength of the spinousprocesses andanticipated physiologicloads in the lumbarspine.Page 6 of 61

TestStatic TorsionTesting AfterRepeatedDeploymentUnder LoadQuantificationandCharacterizationof Wear DebrisKinematic andKineticBehavior inHuman CadaverSpinesTable 1: Laboratory Studies on Superion ISSAcceptancePurposeMethodCriteriaTo evaluate theFive (5) 16mm implants wereMaximumtorsional strength deployed five (5) times each undertorsional strength constant resisting axial load of 300must not beof the SuperionN,andtestedinaccordancewithadverselyISS aftermethodsspecifiedbyASTMF1717affected byrepeatedloadeddeploymentdeployment. Testunder resistingis foraxial load.characterizationonly; noacceptancecriteria wereidentified.To quantify andWear debris generated from 10Types and totalcharacterize anymillion cycle runout samples of size volumetricwear debris8mm and size 16mm implants wasamounts of weargenerated fromquantified and characterized indebris must be of accordance with ASTM F1714.a type andthe Superionamount similar toISS duringother legallydynamic axialmarketed spinalcompressiondevices (10 –testing.12mg).Kinematic andkinetic behavior of the SuperionISS, includingrange of motionand intradiscalpressures, werecharacterized inhuman lumbarspine specimens.Six (6) lumbar spine specimens (L1to S1) were tested. The S1 segmentwas fixed, and a follower load wasused to apply compressive preloadsup to 400N at the L1 segment. Spinespecimens were preconditioned bycycling in each plane (flexion,extension, lateral bending, androtation) to a maximum bendingmoment of 7.5N. Implants(undersized, nominal, andoversized) were placed at 1 and 2levels. Motion of the L1, L2, L3,L4, and L5 vertebrae were thenmeasured, relative to the sacrum,using an optoelectronic motionmeasurement system, andintradiscal pressures were measuredby transducers placed at theimplanted and adjacent levels.PMA P140004: FDA Summary of Safety and Effectiveness DataDemonstration ofnormal flexion,rotational, andlateral bendingranges of motion,and restriction ofextension. Thistest was used togeneratebenchmarkphysiologic dataand there was noacceptancecriteria identified.ResultsMean yield torque was18 N-m. These resultssuggest that the deviceis not adverselyaffected after repeateddeployment.Total titanium debrisamounted to 0.022 mg(8mm) and 0.017 mg(16mm), well below 1012mg deemedacceptable in scientificliterature, and alsolower than wear debrisvolumes seen inpreviouslycleared/approved spinaldevices.Angular displacementwas reduced inextension in allconfigurations, withlittle or no impact uponrotation or lateralbending. These resultssuggest that the devicehas no detrimentalimpact to thekinematics of thefunctional spinalunit(s).Page 7 of 61

TestRole ofSupraspinousLigament inBiomechanicalStabilityEffects ofImplant onCanal andForaminalDimensionsTable 1: Laboratory Studies on Superion ISSAcceptancePurposeMethodCriteriaTo determine ifThree (3) lumbar spine specimensThe Superion unintended(L1 to S1) were dissected into three implant mustdisruption of the(3) L2-L3 motion segments andprovidesupraspinousthree (3) L4-L5 segments. Thesegmentalligament (SSL)caudal vertebral body of each wasstability to aimpactsfixed in a kinematic profilesegment having asegmentalapparatus, and the cephalad bodydisrupted SSLstability afterwas left free to move. A 400Nequal to orplacement of the preload was applied, and segmentsgreater than that were tested intact, with the SSLof an intactSuperion ISS.dilated and a spacer placed, with the segment. This testSSL 50% transected and a spacerwas used toplaced, with the SSL 100%generatetransected with a spacer placed, and benchmarkwith the SSL 100% transected butbending momentwith no spacer placed. Segmentsdata and therewere tested to a maximum bendingwas nomoment of 10N-m in flexion,acceptanceextension, rotation, and lateralcriteria identified.bending.To quantify theeffects of spacerimplantationupon canal andforaminaldimensions.In each test case, motion of thesegment was measured, relative tothe fixed body, using anoptoelectronic motion measurementsystem.Seven (7) human cadaveric lumbarspine segments were dissected intoindividual motion segments, seven(7) each of L2-L3 and L4-L5segments. Each was placed in aframe, with the caudal end fixed,and the cephalad end free to move,to a maximum of 10 flexion and 5 extension. Using CT imaging, keydimensions were measured inneutral, flexion and extension,including canal area, subarticulardiameter, ligamentum flavumthickness, and foraminal height,width, and area.To establish thatplacement of a Superion spacerincreases canaland foraminaldimensions inextension, andreducesligamentumflavum thickness.This test wasused to generatebenchmarkcharacterizationdata and therewas noacceptancecriteria identified.ResultsBending moments of allimplanted specimenswere 100% to 135%greater in extensionthan for an intactspecimen, and 60% to75% greater in flexion.There was no differencein bending momentsbetween the 50% or100% transected SSLsegments, and the intactSSL segments.These results confirmedthat central canal areaand foraminaldimensions increased inextension, with littlechange in neutral orflexion. Ligamentumflavum thicknessdecreased in extension,neutral and flexion.Measurements were acquired on theintact specimens, on the samespecimens after implantation of aspacer, and on the implantedspecimens after 60,000 cycles ofcoupled 15 flexion-extension under400N axial preload.1White A., Panjabi, M., Clinical Biomechanics of the Spine, J.B. Lippincott, Philadelphia. 2nd Edition.PMA P140004: FDA Summary of Safety and Effectiveness DataPage 8 of 61

B. Additional StudiesTestSterilization, Shelf-Life andPackagingTable 2: Additional Studies on Superion ISSMethod and ResultsThe Superion ISS is provided in a sterile package ready for use. TheSuperion ISS is sterilized using a gamma irradiation dose of 25 kGy tosubstantiate a sterility assurance level (SAL) of 10-6. Sterilization validationaccording to ISO 11137, Sterilization of Health Care Products, Parts 1 and 2was conducted to confirm that the sterility of the implant is achieved, and ismaintained by a sterile barrier package. Sterilization validation according toISO 11137, Sterilization of Health Care Products, Part 1 was conducted toconfirm that the recommended sterilization cycle provides sterility of themanual instruments. Shelf life and packaging validation studies, includingpackaging seal and integrity, accelerated aging, and real-time aging testing,were conducted to demonstrate that the device packaging can maintain asterile barrier, with a shelf life of 5 years.BiocompatibilityThe Superion ISS is manufactured from titanium alloy (Ti-6Al-4V ELI)conforming to ASTM F136. This material has a long history of use in medicalimplants with no significant biocompatibility issues, as shown in the literature.MRI CompatibilityNon-clinical testing has demonstrated that the Superion ISS is MRConditional. The preclinical tests included assessments of magnetic fieldinteraction (translational attraction, migration, and torque), radiofrequencyheating, and artifact measurements. All tests conducted were forcharacterization and labeling purposes and acceptance criteria were notestablished. The Superion ISS can be scanned safely at 1.5T or 3.0T underconditions which are identified in the device labeling.X. SUMMARY OF CLINICAL STUDYThe applicant performed a clinical study to determine a reasonable assurance of safety andeffectiveness of the Superion ISS for the treatment of moderate degenerative lumbar spinal stenosis inthe US under IDE #G070118. Data from this clinical study were the basis of the PMA approvaldecision. A summary of the clinical study is presented below.A. Study DesignPatients were treated between June 2008 and December 2011. The database for this PMA reflecteddata collected through July 7, 2014 and included 470 patients. There were 31 investigational sites.The study was a prospective, multi-center, single-blinded, randomized controlled clinical trialcomparing the Superion ISS to a control group consisting of the X-STOP IPD , a legally marketedalternative with similar indications for use. The study evaluated use of the Superion ISS in thetreatment of subjects aged 45 or older suffering from moderate symptoms of neurogenic intermittentclaudication, secondary to a confirmed diagnosis of moderate degenerative lumbar spinal stenosis(LSS) at one or two contiguous levels from L1 to L5, i.e., from the L1-L2 level to the L4-L5 level. Amaximum of 35 investigative sites in the U.S. and up to 10 sites outside the U.S. were approved toenroll subjects into the trial using a 1:1 randomization assignment and an adaptively selected samplesize ranging from 250 to 350 subjects (125-175 enrolled into each group) using a Bayesian adaptivePMA P140004: FDA Summary of Safety and Effectiveness DataPage 9 of 61

design. Up to an additional 50 subjects (25 per group) could be enrolled to allow for loss to follow-up.In addition, prior to initiating the randomized trial, clinical sites were permitted to enroll up to 2 nonrandomized subjects to receive the Superion ISS. A maximum of 70 such additional Superion ISS“training” cases were built into the protocol. Thus, a maximum of 470 subjects were approved to beenrolled into the study. If the study requirements outlined in the Statistical Analysis Plan were metprior to enrolling 470 subjects, the study enrollment could be stopped and the PMA application couldsubsequently be submitted early. An investigative site was defined as a facility or facilities in the samegeneral geographic location if they are under the control of a local Institutional Review Board (IRB).All adverse events (device-related or not) were monitored over the course of the study andradiographic assessments were reviewed by an independent core laboratory. Overall success wasdetermined by data collected during the initial 24 months of follow-up. All device-related adverseevents, major procedure-related, and adjacent-level-related adverse events and therapeutic failuresreported by the clinical investigators were independently adjudicated (for adverse event code, severityand relationship to the device and/or procedure) by a Clinical Events Committee (CEC) composed ofthree independent spine surgeons. In addition, adverse events reported as having unknown orundetermined relationships to the device by the clinical investigators were to be adjudicated by theCEC.After implantation of the Superion ISS or the X-STOP IPD device, each investigator provided apostoperative care regimen individualized to the specific needs of each subject. The regimen includedbut was not limited to: medications, a corset or brace, acupuncture, traction, physical therapy,chiropractic treatment, use of a TENS unit, and massage therapy.Subjects were required to complete a VAS questionnaire to evaluate pain status at discharge followingthe index procedure. At each follow-up visit, subjects were interviewed to determine if they hadexperienced adverse events (AEs) since the previous follow-up visit. A neurological assessment wasperformed for all subjects at baseline and at all follow-up visits. All subjects were required to completethe Zurich Claudication Questionnaire (ZCQ), Oswestry Disability Index (ODI), Visual Analog Scale(VAS), SF-12 and the VertiFlex Superion Patient Satisfaction questionnaires to evaluate disability,function, pain, quality of life, and satisfaction at each follow-up visit.This clinical study was designed as a Bayesian adaptive trial with a minimum of 250 evaluablesubjects and a maximum of 350 evaluable subjects, with an additional adjustment for loss-to-follow-upof 15%. The final sample size in the randomized mITT population consisted of 190 Superion ISS and201 X-STOP IPD control subjects (391 total subjects). The primary hypothesis of this randomizedcontrolled trial was that the clinical performance of the Superion ISS is non-inferior to the clinicalperformance achieved with the active control. The study endpoint was the rate of overall subjectsuccess at 24 months. A subject was considered a success if they were a success on each of the fourindividual primary outcome criteria. The hypotheses tested for this primary study endpoint are asfollows: H0: Superion ISS overall success rate is inferior (Superion ISS rate – Control rate - );HA: Superion ISS overall success rate is non-inferior (Superion ISS rate – Control rate - ).A Bayesian approach was used to test for non-inferiority. If the posterior probability of the alternativehypothesis was at least 95.8%, using non-informative uniform (Beta[1,1]) priors for each success ratethen the claim of non-inferiority would be made. The choice of non-inferiority margin, Δ (i.e., delta)PMA P140004: FDA Summary of Safety and Effectiveness DataPage 10 of 61

was 10% for the overall subject success rate. The value of 0.958 was selected to control the type I errorof this design (type 1 error less than 0.05).An adaptive sample size approach was used to allow for modifications based on interim results, with amaximum of 350 evaluable subjects and a minimum of 250 subjects. The operating characteristics ofthe adaptive design demonstrate 86.3% power when the Superion ISS group was superior to the XSTOP IPD control group by 5% and 73.6% power when the advantage is 2.5%. In these calculations,the X-STOP IPD was assumed to have a 65% success rate.1. Clinical Inclusion and Exclusion CriteriaEnrollment in the Superion ISS study was limited to subjects who met the following inclusioncriteria:1. Male or female subjects 45 years of age.2. Persistent leg/buttock/groin pain, with or without back pain, that is relieved by flexion activities(example: sitting or bending over a shopping cart)3. Subjects who have been symptomatic and undergoing conservative care treatment for at least 6months.4. Diagnosis of degenerative spinal stenosis of the lumbar spine, defined as the narrowing of themidline sagittal spinal canal (central) and/or narrowing between the facet superior articulatingprocess (SAP), the posterior vertebral margin (lateral recess), and the nerve root canal(foraminal).5. Radiographic confirmation of at least moderate spinal stenosis which narrows the central,lateral, or foraminal spinal canal at one or two contiguous levels from L1-L5. Moderate spinalstenosis is defined as 25% to 50% reduction in lateral/central foramen compared to the adjacentlevels, with radiographic confirmation of any one of the following:a. Evidence of thecal sac and/or cauda equina compressionb. Evidence of nerve root impingement (displacement or compression) by either osseousor non-osseous elementsc. Evidence of hypertrophic facets with canal encroachmentNote: All imaging studies used to confirm LSS were completed within 3 months prior toenrollment. Radiographic (imaging) confirmation of LSS included MRI and/or CT. In the case of atransitional L5/L6 segment with a sufficiently prominent L6 spinous process, these subjects wereincluded by a deviation request from the applicant.6. Must present with moderately impaired Physical Function (PF) defined as a score of 2.0 ofthe Zurich Claudication Questionnaire (ZCQ)7. Must be able to sit for 50 minutes without pain and to walk 50 feet or more8. Subjects who are able to give voluntary, written informed consent to participate in this clinicalinvestigation and from whom consent has been obtained9. Subjects, who, in the opinion of the Clinical Investigator, are able to understand this clinicalinvestigation, cooperate with the investigational procedures and are willing to return for all therequired post-treatment follow-ups.PMA P140004: FDA Summary of Safety and Effectiveness DataPage 11 of 61

Subjects were not permitted to enroll in the Superion ISS study if they met any of the followingexclusion criteria:1. Axial back pain only2. Fixed motor deficit3. Diagnosis of lumbar spinal stenosis which requires any direct neural decompression or surgicalintervention other than those required to implant the control or investigational device4. Unremitting pain in any spinal position5. Significant peripheral neuropathy or acute denervation secondary to radiculopathy6. Lumbar spinal stenosis at more than two levels determined pre-operatively to require surgicalintervention7. Significant instability of the lumbar spine as defined by 3mm translation or 5 angulation8. Sustained pathologic fractures of the vertebrae or multiple fractures of the vertebrae and/or hips9. Spondylolisthesis or degenerative spondylolisthesis greater than grade 1 (on a scale of 1-4)10. Spondylolysis (pars fracture)11. Degenerative lumbar scoliosis with a Cobb angle of 10 at treatment level12. Osteopenia or osteoporosis. To confirm eligibility, at the Clinical Investigator’s discretion, thefollowing subjects may have a DEXA scan performed:- Women 65

Feb 20, 2015 · Device Product Code: NQO . Applicant’s Name and Address: VertiFlex , Incorporated . 1351 Calle Avanzado, Suite 100 . San Clemente, CA 92673 . Date(s) of Panel Recommendation: February 20, 2015 . Premarket Approval Application P140004 (PMA) Number: Date of FDA N