NASS Annual Meeting, Artificial Disc Replacement Notes: The Spine Journal, Oct. 2009

[Slackwater]

The Spine Journal
© 2009 Elsevier Inc. All rights reserved

Volume 9, Issue 10, Supplement 1 Link
pp. S1-S244 (October 2009)
Proceedings of the 24th Annual Meeting of the North American Spine Society, NASS 24th Annual Meeting


131. SF-36 Quality of Life Results: ProDisc-L vs. Circumferential Fusion: Results from a Prospective, Randomized, Multicenter Clinical Study

Jeffrey Goldstein MD
aNew York University, New York, NY, USA

PATIENT SAMPLE: Results from the IDE study with 236 randomized
(75 Fusion and 161 ProDisc-L) patients and 458 CA ProDisc-L patients
treated on protocol were evaluated.

CONCLUSIONS: Our results quantify the significant physical impairment
of patients with DDD compared to the U.S. normal population. As
a result of surgery, the patients’ physical and mental health, as measured
by mean SF-36 scores, improved at two years follow-up. The ProDisc-L
patients experienced a greater improvement in the PCS measure. This improvement
was statistically and clinically significant.


132. 2-Level Cervical Disc Arthroplasty: One-Year Clinical Results from Six Centers in a Prospective Randomized IDE Trial

Randall Dryer MD, Todd Lanman MD2, Brett Gunter MD 3 and Isa Canavati MD 4
1Central Texas Spine Institute, LLP, Austin, TX, USA
2Cedars-Sinai Medical Center, Los Angeles, CA, USA
3Columbia, SC, USA
4Fort Wayne, IN, USA

BACKGROUND CONTEXT: The Prestige LP Cervical Disc Prosthesis
consists of two components which articulate through a proprietary ball
and trough design. Titanium Ceramic Composite material provides excellent
wear and imaging performance. Ball and trough designed to allow for
physiological motion in the cervical spine (e.g. flexion/extension and AP
translation, lateral bending, and unconstrained axial rotation.). Dual stabilization
rails engage the vertebral end-plates to provide immediate fixation
and torsional stability. A clinically proven titanium spray provides longterm
fixation through bone integration. Low anterior profile allows for
multi-level placement.

131 patients

CONCLUSIONS: This suggests cervical disc arthroplasty appears to
achieve favorable outcomes at two-year postoperative for patients with
2-level cervical disc disease. Longer term-follow-up is required.

FDA DEVICE/DRUG STATUS: Prestige LP Cervical Disc Prosthesis:
Investigational/Not approved.


133. A Prospective, Randomized, FDA IDE Study of Lumbar TDR with the Kineflex Artificial Disc vs. the Charité Artificial Disc: Evaluation of Clinical Outcomes at 12 Months from a Single Site

Reginald Knight MD1, Benjamin MacLennan MD1, Jeffrey Roh MD1, Paul Schwaegler MD2 and James Robinson MD3
1Orthopedics Intl., Kirkland, WA, USA
2Seattle, WA, USA
3University of Washington, Seattle, WA, USA

58 patients

CONCLUSIONS:This RCT did not demonstrate any differences in operative
morbidity or 1-year clinical outcome between Charite´ and Kineflex
artificial disks for patients with complaints of mechanical low back pain
refractory to nonoperative treatment. Patients who received either kind
of disk demonstrated clinically meaningful reductions in ODI and VAS.

FDA DEVICE/DRUG STATUS:
Kineflex: Investigational/Not approved;
Charite: Approved for this indication.


152. 5-Year Results of the Prospective, Randomized, Multicenter FDA Investigational Device Exemption (IDE) ProDisc-C TDR Clinical Trial

Daniel Murrey MD1, Michael Janssen DO2, Rick Delamarter MD3, Jeffrey Goldstein MD4, Jack Zigler MD5, Bobby Tay MD6 and Bruce Darden Ii MD7
1Charlotte, NC, USA
2Thornton, CO, USA
3The Spine Center at St John's Health Center, Santa Monica, CA, USA
4New York University Hospital for Joint Diseases, New York, NY, USA
5Texas Back Institute, Plano, TX, USA
6University of California, San Francisco, San Francisco, CA, USA
7Orthocarolina Spine Center, Charlotte, NC, USA

BACKGROUND CONTEXT:Cervical total disc replacement (TDR) is
intended to address pain and preserve motion between vertebral bodies
in patients with symptomatic cervical disc disease (SCDD). TDR may prevent
subsequent accelerated degeneration at adjacent disc levels. Previously,
the 2-year follow-up results from the investigational device
exemption (IDE) clinical trial of the ProDisc-C (Synthes Spine Company,
L.P., West Chester, PA) cervical total disc replacement (TDR) were reported.
Up until now, follow-up results of the ProDisc-C study were only
available to this 2 year time point, with longer term results not known.

PATIENT SAMPLE:A total of 236 patients (103 ProDisc-C; 106 ACDF)
were treated.

CONCLUSIONS:Data shows that significant clinical improvement was
maintained in ProDisc-C patients out to 5 years with no deterioration of
outcomes from 2-year results. Specifically, Prodisc-C patients were significantly
less likely to require further surgical treatment than ACDF patients.
These findings support earlier reports that ProDisc-C TDR is a safe, effective
treatment in patients who meet the study criteria.

FDA DEVICE/DRUG STATUS:ProDisc-C: Approved for this
indication.


153. Cervical Facet Degeneration after Total Disc Replacement: 272 Levels in 158 Patients: 5 Year Follow Up

Luiz Pimenta MD, PhDa, Etevaldo Coutinhoa and Leonardo Oliveiraa
aInstituto de Patologia de Coluna, Sao Paulo, Brazil

PATIENT SAMPLE:272 levels in 158 Patients with 5 year follow up.

CONCLUSIONS:The degenerative facet join disease in the cervical
spine after cervical arthroplasty exists. In our proposed classification, the
majority of patients belong to grade I and II. We didn’t find relationship
between the CT scan facet degeneration and clinical results in these stages,
except in grade III and IV that outcomes scales had a worsening. Facet
joint degeneration is a possible consequence of cervical disc arthroplasty.




157. Multiple Level Lumbar ADR Adjacent to Concurrent Anterior Lumbar Interbody Fusion: A Clinical and Radiographic Analysis of Sagittal Motion Preservation at 2-5 Years

Alexandre Rasouli MDa, Rick B. Delamarter MDa, L.E.A. Kanim MAa, Nomaan Ashraf MDa and Brandon Strenge Sr. MDa
aThe Spine Institute at Santa Monica, Santa Monica, CA, USA

BACKGROUND CONTEXT:The ProDisc-L (Synthes Spine, Westchester,
PA) has superior clinical outcomes when compared to lumbar fusion,
with preservation of motion at both surgical and adjacent levels. However,
no previous study has reported on the radiographic characteristics of single
or multiple level lumbar disc replacements adjacent to a concurrent fusion.

PURPOSE:To evaluate clinical outcomes and the range of motion of one,
two, or three level ProDisc-L disc replacements adjacent to a concurrently performed
anterior lumbar interbody fusion (ALIF) construct using InFix
(Abbott Spine, Austin, TX) stand-alone cage.

STUDY DESIGN/SETTING: Prospective Cohort.

PATIENT SAMPLE:Forty-seven patients underwent simultaneous lumbar
ADR at one or more levels and ALIF at L5-S1. Twenty-three patients
had one-level ADR at L4-L5 with an L5-S1 ALIF, nineteen patients had
a two-level ADR (at L3-L4 and L4-L5) with adjacent fusion, four patients
had a three-level ADR (L2-L3, L3-L4, L4-L5) with adjacent fusion, and
one patient underwent a four-level ADR (L1-L4) with adjacent fusion.

Deleted.Text

CONCLUSIONS:Multilevel lumbar arthroplasty is feasible adjacent to
fusion. Patients not only maintained motion at each of the arthroplasty
levels, but the adjacent unoperated segment also demonstrated non-pathologic
motion. At 2-5 years of follow-up, there were no reoperations and
patients demonstrated significant improvement in pain and disability.

FDA DEVICE/DRUG STATUS:
Prodisc-L: Investigational/Not approved; IN-FIX: Investigational/Not approved.


158. The Hybrid ADR: Long-Term Analysis of Sagittal Motion and Clinical Outcome after Concurrent ADR+ALIF (Minimum 2-Year Follow-Up)

Alexandre Rasouli MD1, Rick B. Delamarter MD2, L.E.A. Kanim MA2, Nomaan Ashraf MD2 and Brandon Strenge Sr. MD2
1University of California, Irvine, Newport Coast, CA, USA
2The Spine Institute at Santa Monica, Santa Monica, CA, USA

BACKGROUND CONTEXT: A recent FDA-sponsored randomized controlled
study of the Prodisc-L (Synthes Spine, Westchester, PA) lumbar
disc replacement established superior clinical outcomes with preservation
of motion at both surgical and adjacent levels, as compared to lumbar fusion.
Patients frequently present with pathology at the L4-L5 and L5-S1
levels and are not candidates for arthroplasty at the L5-S1 segment.

PURPOSE:This study sought to evaluate clinical outcomes and the sagittal
range of motion of single-level ProDisc-L ADR adjacent to a concurrent
ALIF (InFix stand-alone cage, Abbott Spine, Austin, TX).

PATIENT SAMPLE: Twenty-three patients (23) underwent simultaneous lumbar
ADR at L4-L5 and ALIF at L5-S1.

METHODS: Patients were evaluated pre-operatively, at six weeks, three
months, six months, and annually for 2-5 years postoperatively with lateral
flexion-extension dynamic films and with completion of Oswestry and
VAS surveys.

RESULTS: Deleted.Text

CONCLUSIONS: The use of the hybrid ADRþALIF construct does not
inhibit the efficacy of fusion at the ALIF level nor does it inhibit preservation
of ROM at the ADR level. Most significantly, the nonoperative level
adjacent to the hybrid construct maintains its preoperative ROM at 2-5
years postoperatively. There were no revision surgeries or reoperations at
adjacent levels. Clinically, patients demonstrate significant improvement
in pain and reduction in disability.

FDA DEVICE/DRUG STATUS: ProDisc-L: Investigational/Not approved;
IN-FIX: Investigational/Not approved.


165. Preliminary 3-Year Results from a Prospective, Randomized, Controlled IDE Study of the Dynesys Dynamic Stabilization System

Reginald Davis MD1, Rick Delamarter MD2, James Maxwell MD3, William Welch MD, FACS, FICS4, Jeffrey Wingate MD5 and John Sherman MD6
1Baltimore, MD, USA
2Santa Monica, CA, USA
3Scottsdate, AZ, USA
4Philadelphia, PA, USA
5Michigan Spine Institute, Waterford, MI, USA
6Twin Cities Orthopaedic, Minneapolis, MN, USA


BACKGROUND CONTEXT:Patients with radicular
pathology due to spondylolisthesis or stenosing lesions are typically
treated with decompression and spinal fusion. A posterior stabilization system
has been developed to stabilize the segment without the need for fusion.
Preliminary long-term outcomes from a cohort of patients in an
IDE clinical trial examining dynamic stabilization with the Dynesys Dynamic
Stabilization System are being reported.


PATIENT SAMPLE:This preliminary data set includes
3-year outcomes from 89 patients following dynamic stabilization (DS) patients
and 45 patients treated with posterolateral fusion (PLF). This cohort
is part of an IDE study which consisted of 253 (DS) and 114 at 28 centers.

RESULTS: Deleted.Text
The revision rate for the DS group was 28% and 23% for the PLF cohort.

CONCLUSIONS: Preliminary long-term clinical outcomes from an IDE clinical trial are reported. At 36 M,

FDA DEVICE/DRUG STATUS:Dynesys: Investigational/Not approved.



187. Injection Treatment Effectively Reduces Lower Back Pain Associated with Lumbar Spinal Stenosis in Older Adults

Virginia Briggs1, Patricia Franklin MD, MPH, MBA2, Thomas McLaughlin1, Wenjun Li PhD1, David Lombardi3, Mark Kaplan MD1 and Mark Eskander MD1
1University of Massachusetts Medical School (Worcester), Worcester, MA, USA
2Worcester, MA, USA
3Liberty Mutual Research Institute, Hopkinton, MA, USA

BACKGROUND CONTEXT: Lumbar spinal stenosis (LSS) is a common
condition that causes pressure on the spinal cord and nerve roots, resulting
in lower back and leg pain. LSS is commonly caused by degenerative
changes in older adults. Treatments to reduce pain include both surgical
and non-surgical interventions. Many physicians and patients choose
non-surgical methods for treatment such as injections. As the proportion
of older adults in the general population grows each year, it is expected
that degenerative changes associated with LSS will increase. Older patients
may likely continue to seek alternative, less invasive treatments for their
lower back pain. However, much of the research to date has been conducted
among younger patients with LSS.

PURPOSE: Injection treatment is a commonly used non-surgical procedure
to alleviate lower back pain. Information is lacking about the effectiveness
of injection treatment, particularly in older adults. This study
quantified the amount of pain relief reported by adults 60 years and over
who were diagnosed with degenerative lumbar spinal stenosis, a common
cause of lower back pain in older adults.

STUDY DESIGN/SETTING: Patients scheduled for injection treatment
were prospectively selected from a high volume spine center.

PATIENT SAMPLE: All patients; 60 years old, who had been diagnosed
with lumbar spinal stenosis and were scheduled to receive an injection for
lower back pain at the Spine Center were eligible. Diagnosis of LSS was
confirmed using Magnetic Resonance Imaging reports and clinical notes.
Exclusion criteria included previous lumbar injection in the past 6
months, lumbar surgery within the past 2 years and history of lumbar
fracture.

OUTCOME MEASURES: The SF-36 Questionnaire is one of the most
frequently used questionnaires to assess health related quality of life in
patients with back pain. In this study, two components were used; the Pain
sub-score of the PCS (primary outcome) and the MCS (covariate).

METHODS: Patients were enrolled between January 1 and July 1, 2008
and followed for 3 months. Post-injection Pain scores were compared to
baseline using T-tests and univariate and multivariate regressions.

RESULTS:Of 78 patients meeting study inclusion criteria, the mean Pain
score at baseline was 28.6, 43.2 at 1 month and 38.0 at 3 months. Deleted.Text

CONCLUSIONS: Injection treatment effectively decreases lower back
pain in older adults with lumbar spinal stenosis. Clinicians will have more
information available about pain relief when discussing treatment options
with their older patients. In addition, higher emotional status increases the
amount of pain relief experienced at 1 month following injection.Deleted.Text

FDA DEVICE/DRUG STATUS:This abstract does not discuss or include
any applicable devices or drugs.


198. Radiographic Range of Motion is Related to Clinical Outcomes in Lumbar Artificial Disc Replacement Patients: One Site Analysis of 219 Patients with Minimum 2 Year Follow-Up, USA-FDA IDE Study

Hyun Bae MD1, L.E.A. Kanim MA1, Michael Kropf MD1 and Rick B. Delamarter MD1
1Spine Research Foundation, Spine Institute, Santa Monica, CA, USA

BACKGROUND CONTEXT:Few studies have reported on the associations
among range of segmental motion (ROM) and outcomes after lumbar
ADR. Maintenance of ROM has been reported at 5 to 10 degrees for Pro-
Disc-L patients. Data on how ROM relates to self-reported outcomes have
not yet been reported yet are also important considerations for efficacy in
evidence based medicine. Since ProDisc-L is intended to allow motion,
there is interest in relationships ROM and self-reported outcomes.

STUDY DESIGN/SETTING: USA-FDA IDE trial, one site.

PATIENT SAMPLE:Randomized (RCT, n=59), Pilot (P, n=6), Continued
Access (CA, n=147) and Compassionate Use (CU, n= 37).

RESULTS:There were a total of 219 ProDisc-L treated patients
(89%) with 24-month data. Deleted.Text

CONCLUSIONS:ROM was maintained throughout follow-up in Pro-
Disc-L patients. Importantly, greater ROM was strongly associated with
greater functional ability, less pain, and greater satisfaction. This is the first
report of these associations.

FDA DEVICE/DRUG STATUS:
ProDisc-L (1-Level): Approved for this indication;
ProDisc-L (multi-level): Investigational/Not approved.



199. Fibrin Injection Stimulates Early Disc Healing in the Porcine Model

Zorica Buser MD1, Fabrice Kuelling MD1, Liu Jane1, Ellen Liebenberg1, Jessica Tang2, Kevin Thorne PhD3, Dezba Coughlin MD1 and Jeffrey Lotz PhD1
1University of California, San Francisco, CA, USA
2University of California, Berkeley, CA, USA
3Spinal Restoration, Austin, TX, USA


PURPOSE: To test the hypothesis that interdiscal application of fibrin
stimulates healing by reducing cytokine levels and stimulating matrix
synthesis.

STUDY DESIGN/SETTING: Full thickness annular injury and nucleotomy
was performed in three lumbar levels in Yucatan mini-pigs using
the DeKompressor (Stryker). These discs were randomized to no-treatment
or fibrin injection. Animals were recovered up to 12 weeks.

OUTCOME MEASURES: Deleted.Text

RESULTS: Nucleotomy Deleted.Text

CONCLUSIONS: In the porcine nucleotomy model, fibrin injection
blunts acute increases in inflammatory cytokine production, promotes
a more rapid recovery of mechanical properties, and enhanced proteoglycan
matrix synthesis.
Deleted.Text

FDA DEVICE/DRUG STATUS:
Biostat Disc Augmentation System: Investigational/
Not approved.


P1. Relationship Between Endplate Morphology and Clinical Outcome of Single-Level Lumbar Disc Arthroplasty


P5. A Prospective Randomized Comparison of Two Lumbar Total Disc Replacements: Results at 24-Month Follow-Up

Richard D. Guyer MD, Kenneth Pettine MD, Michael Duffy MD, Scott L. Blumenthal MD1 and Barton Sachs MD1
1Texas Back Institute, Plano, TX, USA
2Rocky Mountain Association in Orthopedic Medicine, Loveland, CO, USA
3Texas Back Instiute Research Foundation, Plano, TX, USA


PURPOSE: The purpose of this randomized study was to compare the results
of two lumbar TDRs.

STUDY DESIGN/SETTING: Data were combined from two centers participating
in a prospecitve, randomized FDA IDE trial.

PATIENT SAMPLE: Data for a total of 115 patients from two centers,
who have reached 24-month follow-up were included in the outcome
study.

Deleted.text

CONCLUSIONS: This prospective, randomized study found that with respect
to peri-operative data, clinical outcome, adverse events, and radiographic
results, the two artificial discs produced similar results.

FDA DEVICE/DRUG STATUS:
Kineflex-L: Investigational/Not approved;
Charite: Approved for this indication.


P27. Two Year Follow Up In A Metal-On-Metal Lateral Disc Replacement: A Shift Paradigm

Luiz Pimenta MD, PhDa, Etevaldo Coutinhoa and Leonardo Oliveiraa
aInstituto de Patologia de Coluna, Sao Paulo, Brazil

BACKGROUND CONTEXT:Current lumbar total disc replacement
(TDR) devices require an anterior approach for implantation. This approach
has inherent limitations, including risks to abdominal structures,
and resection of the anterior longitudinal ligament (ALL). Placement of
a TDR device from a true lateral (XLIF) approach allows for easier, less
invasive access to the disc space. Lateral implantation of TDR also preserves
the stabilizing ligaments, which are a natural restraint to excessive
rotations and translations, and thereby help to minimize facet stresses. Importantly,
implantation from a lateral approach leaves greater opportunity
for safer revision surgery, if necessary, by avoiding scarring of anterior
vasculature. Additionally, the footprint of the lateral TDR device capitalizes
on the biomechanical support of the ring apophysis.

PURPOSE: Here we present our data supporting the use of an artificial
disc replacement inserted by XLIF approach.

STUDY DESIGN/SETTING: Prospective, non-randomized, single center
clinical study.

PATIENT SAMPLE: Patients included
16 males and 20 females, averageage 43 yrs (24-60).
Surgeries included 14 1-level, 3 2-level, and 19 hybrid TDR/ALIF cases.

METHODS: A TDR device designed for implantation through a true lateral,
retroperitoneal, transpsoas approach (XLIF) was implanted in 36 patients
with discography-confirmed 1- or 2-level DDD. Clinical and
radiographic outcomes assessments were prospectively collected.

RESULTS:Surgeries included 14 1-level, 3 2-level, and 19 hybrid TDR/
ALIF cases.

Deleted.Text

CONCLUSIONS:Our results of a laterally placed TDR device demonstrate
maintenance of pain relief and functional improvement. The benefits
of this technique – minimal morbidity, avoiding mobilization of the great
vessels, preserving the anterior longitudinal ligament, biomechanically stable
orientation, and broader revision options – suggest a promising new direction
for TDR procedures.

FDA DEVICE/DRUG STATUS:
Lateral Total Disc Replacement: Investigational / Not approved.


P64. Patient Clinical Outcomes and Motion at 1 Year Follow-Up: Cervicore Disc Replacement vs. Fusion

Jean-Jaques Abitbol MD1, Neill Wright MD2 and Nevan Baldwin MD3
1San Diego, CA, USA
2Washington University in St. Louis, St. Louis, MO, USA
3Covenant Hospital, Lubbock, TX, USA

STUDY DESIGN/SETTING: Data was collected from 4 study sites participating
in the FDA approved CerviCore US IDE trial at 6 weeks, 3, 6,
and 12 months following surgery.

PATIENT SAMPLE:Patients were randomized to either ACDF (41 patients)
or disc replacement with the CerviCore (39 patients).

CONCLUSIONS: Clinical outcomes (VAS and NDI) were comparable
for both treatment groups. By permitting motion, CerviCore may reduce
adjacent level disease. Full 25 site data is needed to confirm these preliminary
results.


P78. Hybrid, Multilevel Lumbar Spine Arthroplasty Using an In Situ Cured, Polyurethane Nucleus Replacement Device in Conjunction with Total Disc Replacement

Michael Lee MD1, Michael Dahl PhD2, Anthony Tsantrizos PhD3 and Randal Ching PhD1
1University of Washington, Seattle, WA, USA
2Disc Dynamics, Inc., Eden Prairie, MN, USA
3Synthes Spine Company L.P., West Chester, PA, USA

BACKGROUND CONTEXT: Degenerative disc disease (DDD) frequently
manifests as a multilevel pathology, with a varying severity of deterioration
across spinal levels. The utilization of only one type of
treatment or device can be insufficient or excessively invasive. Providing
treatment for only the most severely degenerated level may not completely
alleviate pain and therefore may not meet patient expectations or clinical
success. Furthermore, utilizing the most biofidelic and conservative treatment
option in terms of minimally invasive device implantation leaves
more invasive treatment options available in the future should the treatment
fail.

PURPOSE: Evaluate the multi-directional flexibility of a multilevel hybrid
construct consisting of a total disc replacement (TDR) and an in situ,
conforming polyurethane nucleus replacement (NR) compared to 1) single-
level device applications and 2) two-level fusion.

STUDY DESIGN/SETTING:A cadaveric biomechanical study.

CONCLUSIONS: This study demonstrated that both an individual and
a combined multilevel hybrid construct (NR ‘‘topping off’’ a TDR) display
statistically similar kinematics when compared to intact.

Deleted.Text

FDA DEVICE/DRUG STATUS:
DASCOR: Investigational/Not approved;
PRODISC-L: Approved for this indication; Click’X: Approved
for this indication.


P127. Three Year Results from Four Study Sites: Flexicore Intervertebral Disc vs. Fusion

James Zucherman MD1, Eric Woodard MD2, Charles Theofilos MD3 and Rick Sasso MD4
1San Francisco, CA, USA
2Boston, MA, USA
3Palm Beach Gardens, FL, USA
4Indianapolis, IN, USA


PATIENT SAMPLE: Complete data is available for (FlexiCore vs. fusion):
77 vs. 37 patients at pre-op and 47 vs. 20 patients at 3 years.

CONCLUSIONS: Both treatments resulted in reduction of pain; however,
FlexiCore patients’ self-assessed health status was better, indicated by the
higher scores, as compared to fusion. These limited results suggest that
FlexiCore may be an alternative treatment for DDD. Full study data is
needed to confirm these results.

FDA DEVICE/DRUG STATUS:FlexiCore: Investigational/Not approved.


P139. Discover Artificial Disc IDE Trial: Preliminary Results in a Multi-Center Randomized Controlled Trial for Treatment of Single-Level Cervical Disc Disease

Phillip A. Tibbs MD1, James Yue MD2, Mark Shaffrey MD3 and Domagoj Coric MD4
1University of Kentucky, Lexington, KY, USA
2Yale University, New Haven, CT, USA
3University of Virginia, Charlottesville, VA, USA
4Charlotte, NC, USA


PATIENT SAMPLE: 145 patients (85 treated with the DISCOVER disc
and 60 treated with ACDF) enrolled as of February 10, 2009.

CONCLUSIONS: Interim analysis of data from this study suggests that
cervical arthroplasty with the DISCOVER Artificial Cervical Disc may offer
patients with symptomatic single-level cervical degeneration another
option to treat their condition.

FDA DEVICE/DRUG STATUS: Discover Artificial Cervical Disc: Investigational/Not approved.



P162. Three-Level Lumbar ADR: A Clinical and Radiographic Analysis of Sagittal Motion Preservation at 2-6 Years

Rick B Delamarter MD1, Alexandre Rasouli MD2, L.E.A. Kanim MA1, Nomaan Ashraf MD1, Brandon Strenge MD1, Michael Kropf MD1 and Hyun Bae MD1
1The Spine Institute at Santa Monica, Santa Monica, CA, USA
2The Spine Institute, Santa Monica, CA, USA

BACKGROUND CONTEXT: The FDA-sponsored randomized controlled
study of the Prodisc-L (Synthes Spine, Westchester, PA) lumbar
disc replacement established superior clinical outcomes with preservation
of motion at both surgical and adjacent levels, as compared to lumbar fusion.
However, no previous study has reported on the radiographic characteristics
of adjacent three-level lumbar disc replacements.

PURPOSE: To evaluate clinical outcomes and the sagittal range of motion
of three-level ProDisc-L disc replacements as well as motion at the adjacent
unoperated segment.

STUDY DESIGN/SETTING: Prospective Cohort.

PATIENT SAMPLE: Forty-one patients receiving three-level adjacent
ADR between L2 and S1.

CONCLUSIONS: The use of the three-level Prodisc-L ADR construct
does not inhibit preservation of range of motion at the individual ADR
levels. The nonoperative level adjacent to the construct maintains its preoperative
range of motion at 2-6 years postoperatively. There was 0.02%
reoperation rate for conversion to fusion and no operations at adjacent
levels. Improvements in pain and disability were significant.

FDADEVICE/DRUGSTATUS:ProDisc-L: Investigational/Not approved.