Literature FDA labeling status 
`
`
`
`The following material describes off‐label usage of 
`NuVasive, Inc. product(s) in the United States 
` 
` 
` 
` 
`The following scientific literature describes the use of NuVasive, Inc. products outside of the 
`scope of their approval or clearance from the US Food and Drug Administration, otherwise 
`known as off‐label usage. As such, these materials are intended for internal use as educational 
`materials. Discussion with or distribution of these materials to healthcare professionals (HCPs) 
`within the United States is prohibited unless an unsolicited request for such information was 
`made by the HCP. If so, please follow the Unsolicited Request for Off‐label Literature Policy and 
`submit a completed unsolicited request form and fax it to (858) 320‐4630. 
` 
` 
`If you have any questions, please don’t hesitate to contact me directly. 
`
` 
` 
` 
` 
` 
`
` 
` 
`
` 
`
` 
`Kyle Malone, MS 
`Manager, Clinical Resources 
`Direct: 858 320 4530 
`Fax: 858 320 4630 
`Email: kmalone@nuvasive.com 
`7475 Lusk Boulevard, San Diego, CA 92121 
`
`
` 
`
` 
`
` 
`
` 
`
`  
`
`
`
`
`
`1
`
`NUVASIVE 1054
`NuVasive, Inc. v. Warsaw Orthopedic, Inc.
`IPR2013-00206
`IPR2013-00208
`
`

`

`Orthopaedic Surgery Spine
`
`Experience and Early Results with a Minimally Invasive Technique for Anterior
`Column Support Through eXtreme Lateral Interbody Fusion (XLIF®)
`
`a report by
`W Blake Rodgers , MD , Curtis S Cox , MD and Edward J Gerber , PA
`
`Spine Midwest, Inc.
`
`Anterior approaches to the lumbar spine allow for the indirect
`decompression of the spinal canal and neural foramina by placement of a
`large interbody graft to reconstruct the anterior column. The risks
`associated with the traditional anterior approach include injury to the
`abdominal contents, iliac vasculature, or sympathetic plexus—including the
`risk of sexual dysfunction.1 Posterior lumbar interbody fusion (PLIF) and
`transforaminal lumbar interbody fusion (TLIF) approaches avoid many of
`the risks associated with the anterior approach, but carry their own sets of
`concerns—devitalization of the paraspinous musculature, inadvertent
`duratomy, and traction neuropraxia.2–3 Minimally invasive posterior
`techniques have obviated some of the exposure-related morbidity, but
`provide a challenging surgical corridor for placement of an adequately
`sized interbody graft.3
`
`A novel, minimally disruptive spine procedure called the extreme lateral
`interbody fusion or XLIF® (NuVasive® Inc., San Diego, CA) is a 90° off-
`midline or direct lateral approach that allows for large graft placement
`and excellent disc height restoration, and provides indirect decompression
`of the stenotic motion segment.4–6 This approach can be performed using
`two 3–4cm skin incisions. Safe passage through the retroperitoneal space
`is assured by gentle blunt dissection. The psoas muscle is traversed, and
`the lumbar plexus protected, by the use of automated electrophysiology
`(NeuroVision® JJB, NuVasive Inc.). Exposure is achieved with an
`expandable three-bladed retractor (MaXcess®, NuVasive Inc.), which
`allows for direct illuminated visualization facilitating discectomy and
`complete anterior column stabilization using a large load-bearing implant.
`Since the introduction of the XLIF technique to North America in late
`2003, a host of advantages for our patients have become apparent:
`
`leads to quicker recovery and decreased
`
`• less tissue damage
`narcotic requirements;
`• it is widely applicable to a host of degenerative spinal conditions;
`• it is safe and reproducible with few complications due to the use of
`automated neuromonitoring (NeuroVision®);
`
`W Blake Rodgers, MD, practices at Spine Midwest, Inc., and is
`Medical Director of the Spine Center at St Mary’s Health Center
`in Jefferson City, MO. Dr Rodgers also serves on the Board of
`Directors of the Association Européenne des Groupes de
`Recherche pour l’Osteosynthese Rachidienne (ARGOS), the
`Society of Lateral Access Surgery (SOLAS), and St Mary’s Health
`Center. He is Associate Editor of ARGOS Spine News and
`Chairman of the SOLAS Research Committee.
`
`E: brodgers@spinemidwest.com
`
`• the large, load-bearing interbody construct provides disc space distraction,
`indirect decompression, sagittal alignment correction, and stability; and
`• improved efficiency resulting in shorter operating room (OR) time and
`decreased length of stay.
`
`eXtreme Lateral Interbody Fusion Surgical Technique
`The surgical technique has been described in detail by Heim et al.4 and
`Ozgur et al.5 The safety and reproducibility of the technique have been
`demonstrated in several retrospective reviews7–10 at multiple centers.
`Experience has taught us that there are five key steps to making XLIF a safe,
`simple, and efficacious procedure:
`
`• careful patient positioning;
`• gentle retroperitoneal dissection;
`• meticulous psoas traverse using neurovision;
`• complete disc removal and fusion site preparation; and
`• proper interbody implant placement.
`
`Careful Patient Positioning
`It is imperative that the approach be directly lateral to the operative level.
`To facilitate the surgery, the intervertebral axis should be orthogonal to the
`floor of the operating theater and there should be no rotation of the spine
`relative to the plane of operation. Proper orientation is assured by
`positioning the patient such that true lateral and anterior–posterior (AP)
`fluoroscopic images are in use at all times. This is achieved by taking the
`time to be certain that the pedicles overlay one another in the lateral
`projection and that the spinous process is centered between the pedicles
`on the AP image. The table break point should be located between the
`greater trochanter and the iliac wing. The patient must be securely taped
`in place prior to flexing the table in order to gain space between the iliac
`crest and the twelfth rib, as shown in Figure 1—this will allow access of
`levels L4–5 to L1–2.
`
`Gentle Retroperitoneal Dissection
`Experience has dictated that safe and reproducible passage through the
`retroperitoneal space is achieved with two incisions and gentle, blunt
`finger dissection.4,10
`
`Meticulous Psoas Traverse Using NeuroVision
`It is impossible to overemphasize the importance of reliable, timely
`monitoring of the neural elements as the surgeon traverses the psoas. Visual
`identification of the lumbar plexus is not possible, but the plexus can be
`protected by using an automated electrophysiology technology. The
`NeuroVision system, in detection mode, uses a patented hunting algorithm
`
`28
`
`© T O U C H B R I E F I N G S 2 0 0 7
`
`2
`
`

`

`Experience and Early Results with a Minimally Invasive Technique for Anterior Column Support
`
`that provides five pulses of increasing amplitude current per second until a
`recording myotome has responded. Once the maximum current level to
`elicit a response is achieved, the current output will stabilize at this level.
`
`Figure 1: Proper Patient Positioning
`
`Observations made from direct nerve stimulation during instrumentation
`procedures have
`found
`that clinically normal nerves elicit an
`electromyogram (EMG) response under an applied stimulus ranging from 1
`to 5mA, with an average of about 2mA.11,12 Therefore, the closer the
`proximity of the nerve, the closer the threshold will be to 2mA. Experience
`with lateral approach procedures has shown that thresholds >10mA provide
`a distance from nerves that allows adequate exposure to the disc.
`
`The NeuroVision JJB System displays the stimulus responses on a color-
`coded, numerical graphical user interface (GUI). The responses are also
`accompanied by an audible tone whereby changes in tone indicate the
`change in color-coding, allowing the surgeon the freedom to focus on the
`surgical site instead of the screen. Lateral approaches have been employed
`in the past and—without the use of realtime, surgeon-driven
`electrophysiology—have resulted in relatively high complication rates of
`post-operative thigh paresthesias in approximately six patients, or 30%. The
`paresthesia resolved within four weeks in four of these six patients.13
`
`Complete Disc Removal and Fusion Site Preparation
`As previously described in more detail,4–6 exposure is achieved with an
`expandable three-bladed retractor (MaXcess, NuVasive Inc.), which allows
`for direct illuminated visualization. The retractor system is attached firmly to
`the operating table with an articulating arm. An important feature of the
`retractor is the ability to stabilize the most dorsally oriented blade using an
`intradiscal shim, thus protecting the lumbar plexus from being compressed
`against the transverse process. The stabilization of the posterior blade
`allows the anterior blades to be safely deployed to create sufficient access
`space for discectomy and implant placement.
`
`Proper Interbody Implant Placement
`The XLIF approach allows for complete anterior column stabilization
`using a large, load-bearing implant. Another important aspect of the
`surgical technique is the release of the contralateral annulus and the
`selection of an implant that is large enough to span the ring apophysis,
`as shown in Figure 2.
`
`Early American Experience
`Proper training is vital for a technique as novel as XLIF. After the initial
`descriptions by Pimenta4,5
`in Brazil, the technology was introduced to
`surgeons in the US. The early experience with XLIF in the US was reported
`by Wright.10 The first 145 patients (166 levels) treated by 20 surgeons
`presented with multiple indications. The distribution of procedures and
`levels in this early experience was:
`
`L4–L5
`L3–L4
`L2–L3
`
`63 (52%)
`43 (35%)
`16 (13%)
`
`Single-level
`Two-level
`Three-level
`
`79%
`20%
`1%
`
`Figure 2: Implant Placement
`
`Left: red zone indicates the strongest region of the anterior vertebral column 14. Right: position of
`the XLIF implant on the strongest bone—the ring apophysis.
`
`• 81% of patients had supplemental fixation;
`• the average surgical time was 74 minutes/level;
`• the average hospital stay was one day; and
`• the average blood loss was <100cc.
`
`Most importantly, there were no vascular or visceral injuries reported in this
`large clinical series. There were two cases of transient thigh numbness
`(ipsilateral to the approach), which resolved within two weeks. Five patients
`reported transient hip flexor weakness—these symptoms resolved one to
`eight weeks post-operatively in all five.
`
`Expanded Indications
`After the technique was shown to be safe and reproducible, a variety of
`expanded surgical indications have been described, including degenerative
`disc disease (DDD) with instability, post-laminectomy instability, junctional
`disease, or, adjacent to previous fusion, recurrent disc herniation,
`degenerative spondylolisthesis
`(grade 2), degenerative scoliosis,
`pseudarthrosis, discitis, vertebral osteomyelitis (without active infection),
`and revision of failed total disc replacement (TDR).
`
`While traversing the psoas with a muscle-splitting approach, NeuroVision
`identified nearby nerves at risk in 46% of the cases—reinforcing the
`importance of reliable automated electrophysiology. Wright et al.10 summarized
`their findings as follows:
`
`The two indications that have been proved most rewarding for patients are
`adjacent segment degeneration and degenerative scoliosis—which typically
`affects older patients with significant comorbidities who are unable to
`tolerate large, disruptive surgeries.
`
`U S M U S C U L O S K E L E T A L R E V I E W 2 0 0 7
`
`29
`
`3
`
`

`

`Orthopaedic Surgery Spine
`
`Figure 3: Lateral and Anterior–Posterior Radiographs Three Months After L4–5 eXtreme Lateral Interbody Fusion for Adjacent Segment
`Degeneration Above an L5–S1 Anterior Lumbar Interbody Fusion
`
`For surgery adjacent to fused levels, the lateral approach allows the
`surgeon to avoid the previously operated approach pathway—either
`dorsally or ventrally. Reconstruction of the anterior column
`is
`(CoRoent® XL).
`accomplished by
`the
`large
`interbody
`implant
`Supplemental fixation can be applied with percutaneous pedicle screws
`(SpheRx DBR®) (see Figure 3) or, if the surgeon prefers, with a recently
`designed lateral lumbar plate (XLP™).15
`
`Even more exciting is the use of XLIF in elderly patients with significant
`scoliosis. Phillips and Pimenta7 have summarized the results of their
`prospective study of XLIF treatment of degenerative scoliosis. An example
`of three-level correction on a 72-year-old patient is shown in Figure 4. Of
`particular note is the correction of the rotational deformity in addition to the
`coronal deformity, as seen by the alignment of the spinous processes in the
`post-operative radiograph. In brief, their findings from this two-year follow-
`up study included a reduction in Owestry Disability Index (ODI) from a pre-
`operative value of 49.0 to a two-year average value of 21.4. The Visual
`Analog Scale (VAS) score for pain reduced from a pre-operative value of 9.1
`to a two-year average value of 5.1. The Cobb angle was reduced from an
`average pre-operative value of 18° to an average post-operative value of 8°.
`The lordosis increased from a pre-operative average value of 34° to a post-
`operative average value of 41°.
`
`Personal Experience
`The prospective series of our first 100 patients treated with XLIF has been most
`encouraging. One hundred patients (122 levels) were operated on by the
`senior surgeon. Their primary diagnoses were stenosis (33), spondylolisthesis
`(23), degenerative disc disease (18), post-laminectomy instability (14),
`herniated nucleus pulposus (HNP) (7), and scoliosis (5). Eighty patients had
`concomitant deformity of scoliosis (17) or spondylolisthesis (63).
`
`The distribution of procedures and levels was:
`
`37%
`33%
`24%
`6%
`
`Single-level
`Two-level
`Three-level
`Four-level
`
`72%
`22%
`5%
`1%
`
`L4–L5
`L3–L4
`L2–L3
`L1–L2
`
`30
`
`Figure 4: Pre- and Post-operative Anterior–Posterior and Lateral
`Radiographs of Degenerative Scoliosis
`
`Three levels were staged and treated without posterior instrumentation.7
`
`In 99 cases supplemental posterior fixation was used—unilateral pedicle
`screw-rod constructs (79), bilateral pedicle screw-rod constructs (8), and
`trans-facetal screws (12). It is our impression that facet screws allow more
`settling of the graft than pedicle screw-rod constructs. Unilateral pedicle
`screw-rod constructs appear to be as clinically stable as bilateral constructs
`
`U S M U S C U L O S K E L E T A L R E V I E W 2 0 0 7
`
`4
`
`

`

`Orthopaedic Surgery Spine
`
`Figure 5: Pre- and Post-operative Lateral Radiographs of L4–5 Spondylolisthesis Treated with eXtreme Lateral Interbody Fusion
`
`and biomechanical data suggest that this fixation should be adequate.15
`
`Results were as follows:
`
`Average length of stay (days): 1.5
`
`Hemoglobin change (pre-op/post-op) (g):
`Pre-op
`6
`
`Disc height (mm):
`
`1.71
`Post-op
`10
`
`Range: 0–4.2
`3 months
`10
`
`6 months
`9
`
`Spondylolisthesis (63 levels) (see Figure 5)
`Slip (mm):
`4.3
`Scoliosis (17 cases) (degrees):
`17.9
`Lenke score:16
`VAS:
`
`8.3
`
`0.5
`9.7
`
`0.8
`13.4
`2.1
`2.4
`
`1.8
`
`1.6
`2.6
`
`Complications:
`
`Ileus 2
`Transient weakness tibialis anterior 1
`
`Post-operative thigh discomfort was routine, and slight lateral thigh
`numbness rare. These symptoms resolved completely within four to six
`weeks in all cases. The patient with transient tibialis anterior weakness
`had complete recovery by six weeks post-operatively. No significant hip
`flexor weakness was noted beyond six weeks. There were no wound
`infections and no patient required blood transfusion.
`
`Conclusion
`XLIF technology is revolutionizing the care of patients needing
`thoracolumbar spinal fusion between T6–7 and L4–5. More rapid
`recovery is facilitated by decreased tissue trauma.
`
`By adhering to the five key steps, spinal surgeons can employ
`this technique safely and reproducibly. It is vital that we attend to
`careful positioning and employ reliable neuromonitoring as we
`meticulously traverse the psoas in order to offer our patients the results
`they deserve. ■
`
`1.
`
`2.
`
`3.
`
`Sasso R, et al., Analysis of operative complications in a series of
`471 anterior lumbar interbody fusion procedures, Spine,
`2005;30(6):670–74.
`Park Y, Ha JW, Comparison of one-level posterior lumbar
`interbody fusion performed with a minimally invasive
`approach or a traditional open approach, Spine,
`2007;32(5):537–43.
`Salerni AA, A minimally invasive approach for posterior lumbar
`interbody fusion, Neurosurg Focus, 2002;13(6):e6.
`4. Heim SE, Pimenta L, Surgical Anatomy and Approaches to the
`Anterior Lumbar and Lumbosacral Spine. In: DH Kim, AR Vaccaro,
`RG Fessler (eds), Spinal Instrumentation Surgical Techniques,
`Thieme Medical Publishers, 2005;706–11.
`5. Ozgur BM, Aryan HE, Pimenta L, Taylor WR, Extreme Lateral
`Interbody Fusion (XLIF): a novel surgical technique for anterior
`lumbar interbody fusion, Spine J, 2006;v6:435–43.
`Pimenta L, Diaz RC, Guerrero LG, Charite lumbar artificial disc
`retrieval: use of a lateral minimally invasive technique, J Neurosurg
`
`6.
`
`32
`
`7.
`
`8.
`
`Sp, 2006;v5:556–61.
`Phillips F, Diaz R, Pimenta L, Minimally-invasive fusion (XLIF®) in
`the treatment of symptomatic degenerative lumbar scoliosis.
`Poster presented at North American Spine Society, 2005,
`Philadelphia, PA.
`Smith W, XLIF: One surgeon’s interbody fusion technique of
`choice. Poster presented at AANS/CNS Joint Section on Spine,
`2006, Orlando, FL.
`9. Hyde J, Seits M, Mid- to long-term follow-up of patients with XLIF
`treatment of lumbar degenerative conditions. International
`Meeting on Advanced Spine Techniques, 2007, Paradise Island,
`Bahamas.
`10. Wright N, XLIF- the United States experience 2003–4,
`International Meeting on Advanced Spine Techniques, 2005, Banff,
`Canada.
`11. Calancie B, Madsen P, Lebwohl N, Stimulus-evoked EMG monitoring
`during transpedicular lumbosacral spine instrumentation: Initial
`clinical results, Spine, 1994;19(24):2780–86.
`
`12. Maguire J, Wallace S, Madiga R, et al., Evaluation of intrapedicular
`screw position using intraoperative evoked electromyography,
`Spine, 1995;20(9):1068–74.
`13. Bergey D, Villavicanero AT, Goldstein T, Regan JJ, Endoscopic
`lateral trans-psoas approach to the lumbar spine, Spine,
`2004;29:1681–8.
`14. Grant JP, Oxland TR, Dvorak MF, Mapping the structural
`properties of the lumbosacral vertebral endplates, Spine,
`2001;26(8):889–96.
`15. Bess RS, Bacchus K, Vance R, Lumbar Biomechanics with Extreme
`Lateral Interbody Fusion (XLIF®) Cage Construct. International
`Meeting on Advanced Spine Techniques, 2007, Paradise Island,
`Bahamas.
`16. Bridwell K, Lenke G, McEnery K, Anterior fresh frozen structural
`allografts in the thoracic and lumar spine do they work if
`combined with posterior fusion and instrumentation in adult
`patients with kyphosis or anterior column defects?, Spine,
`1995;20(12):1410–18.
`
`U S M U S C U L O S K E L E T A L R E V I E W 2 0 0 7
`
`5
`
`