Cervical Disc Replacement A new option for two-level cervical - - PowerPoint PPT Presentation

A new option for two-level cervical spine surgery

Cervical Disc Replacement

• Medical School:
• University of Western Ontario
• Residency:
• Neurosurgery
• University of Western Ontario
• Professional Affiliations:
• Fellow, Royal College of Surgeons
• Fellow, American College of Surgeons
• American Board of Neurological Surgery

Darrell C. Brett, MD Northwest Spine and Brain Surgery

Introduction

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There are approximately 1.1 million patients each year in the United States that suffer from symptomatic cervical disc disease1. This condition can significantly affect a person’ s ability to sleep, work, drive, participate in recreation or exercise, and many other critical functions of daily life. The answer for relief of pain for many of these patients has been neck fusion surgery since the 1960’

• s. Over the years, our understanding of the long-term

effects and consequences of fusion, as well as alternative treatments, has grown tremendously. In the early 2000’ s research and development for cervical disc replacement began with a proliferation of designs entering rigorous clinical studies. The goal for disc replacement was to accomplish the same pain relief as fusion while maintaining physiologic motion in order to prevent adjacent segment degeneration. Between the years 2009 – 2013, the FDA approved 6 disc replacement devices in the United States. All of these devices compared their clinical results to neck fusion2.

Arm Pain / Neck Pain Patient Presentation

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• With aging, the intervertebral

discs lose water (dehydrate) and decrease in height.

• The daily motion patterns of the

highly mobile cervical spine can wear down dehydrated discs even further, causing the disc(s) to bulge and surrounding bone structures to produce spurs.

• Bulging discs and bone spurs

can press on sensitive nerve structures, causing pain and

• ther symptoms.

Neck Pathology - Causes

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Patients with herniated disc(s) often present with one or more of the following symptoms:

• Pain in the neck, shoulder, and arm(s) –

with

• r without neck movement
• Neck stiffness
• Numbness, tingling, or weakness in the

hands

• Weak or absent upper extremity reflexes
• Weakness in the lower extremities or effects
• n walking gait (if spinal cord involvement)
• Headaches

Common affects on the functions of daily life:

• Difficulty driving –

turning of the head

• Difficulty lifting objects
• Difficulty working, reading, concentrating
• Difficulty with personal care (washing,

dressing)

• Effects on recreational activities /

exercise

Patient Symptoms & Effects on Daily Life

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Treatment Options

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Conservative Care

The standard initial treatment regimen involves 6 weeks of conservative (non-surgical) care:

• 1. Rest, activity modifications
• 2. Physical therapy, controlled

exercises, stretches, bracing

• 3. Anti-inflammatory and analgesic

medications

• 4. Chiropractic treatments, cervical

traction

• 5. Pain injections /blocks
• 6. Acupuncture

If no relief, or symptoms get progressively worse, various surgical

• ptions can be discussed

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Removal of bone and tissue that is compressing the nerve root through minimal incisions, utilizing endoscopic tubes, cameras, and instruments Removal of a portion of a bony posterior arch (lamina) and associated ligaments that surround the spinal cord, leading to relief of pressure on nerve tissues

Surgical Management: Outpatient / Minimally Invasive

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Laminectomy Foraminotomy

Anterior Cervical Discectomy and Fusion (ACDF) is an inpatient or outpatient surgical procedure where:

• The bulging disc is removed
• Neural structures are relieved of pressure and pain
• A bone spacer or plastic/metallic implant is placed

in the disc space to restore disc height and fuse the vertebrae together

• Often, a metal plate is placed on the front of the

vertebrae to help stabilize the segment until fusion

• ccurs

Surgical Management: ACDF or “Fusion”

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Example of a two-level fusion from C5-C7

Fusion has been used successfully for more than 50 years and is very familiar to most spine surgeons. However, fusion changes the normal biomechanics of the cervical spine with potential long-term consequences.

A disc replacement procedure is an inpatient or outpatient surgical

• ption instead of fusion where:
• The bulging disc is removed and the

neural structures are relieved from pressure and pain

• A disc replacement device is placed in the

disc space that restores and maintains disc height, while allowing natural neck motion to continue

Surgical Management: Disc Replacement

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Example of a two-level disc replacement from C5-C7

Disc replacement has been used for more than 20 years globally with proven clinical

• results. Disc replacement is designed to maintain normal cervical spine

biomechanics and has demonstrated certain clinical advantages over fusion.

Total Disc Replacement vs Fusion

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Pain relief from fusion comes with consequences

• Fusion changes the normal biomechanics of the spine. The levels above and

below the fusion compensate for the loss of motion at the fused level by taking

• n significantly more motion and stress3

Multiple clinical studies comparing fusion to disc replacement have shown:

• 2-6x higher reoperation rates for fusion patients4,5,6
• Increased radiographic adjacent level degeneration for fusion patients7,8,9

Lessons Learned: Long-Term Effects of Fusion

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1977 1984 1989

Adjacent Segment Degeneration10

Disc replacements are designed to maintain physiologic motion and minimize the downsides of fusion

IDE clinical studies have shown for disc replacement vs fusion:6,11,12,13

In Contrast: Clinical Results of Cervical Disc Replacement

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Up to 3.5x less

Less radiographic adjacent level degeneration

Almost 4x fewer

Fewer reoperations

Up to 16.5% better

Better disability improvement

Up to 7 years out

Maintenance

• f motion

Up to 3 weeks faster

Faster return to work

Mobi-C History and Design

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• Designed by experienced French surgeon team
• First implanted –

November 2004 in Orleans, France

• Over 75,000 devices implanted
• Entered into FDA IDE one and two-level studies in 2006 (FDA approved

August 2013)

History of Mobi-C

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Mobi-C Design Optimized Design for Two-Level Use

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Featuring mobile core technology designed to replicate natural cervical motion

Mobi-C features:

• 3-piece design constructed from proven
• rthopedic materials
• Self-adjusting mobile core that moves with

the spine, designed to facilitate natural motion

• Bone sparing design with no need for keel

cuts, bone chiseling, or screw fixation

• Lateral teeth for stable fixation
• Ease of implantation, with less surgical steps

Key Results of the Mobi-C FDA Clinical Trial

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The Mobi-C Clinical Study is the largest concurrent cervical disc clinical trial ever conducted

• The study was conducted at 24 centers in the U.S. with 59 operating

surgeons

• 599 patients were involved in the Mobi-C one and two-level study
• 647 levels of Mobi-C were implanted during the study
• Patients were randomized to receive either Mobi-C or ACDF with

allograft bone and anterior cervical plate

• Two-year results were submitted to the FDA for product approval;

study patients are followed for 7 years

• Mobi-C received FDA approval in August 2013 for both one and

two-level indications

Mobi-C Study Overview

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Clinical Outcomes

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Mobi-C two-level patients consistently demonstrated less adjacent segment degeneration than fusion patients through 5 years14

• Patients x-rays were analyzed at every study visit to evaluate disc height and bony

changes compared to baseline

Adjacent Segment Degeneration Through 5 Years

Radiographic ASD defined by the Kellgren-Lawrence scale15 Independent radiographic analysis by MMI, Houston, Texas 22

Patients that required removal, reoperation, revision, or supplemental fixation at the index level were considered study failures Mobi-C subjects had fewer subsequent surgeries compared to ACDF subjects through 60 months

Secondary Surgeries Through 5 Years

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Patient x-rays were measured for flexion/extension and side bending angles at every study visit Mobi-C patients demonstrated on average:

• Improvement from baseline that is maintained through 5 years
• Motion in a physiological range through 5 years15

Range of Motion Through 5 Years

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• A patient self-assessment (NDI) was administered and scored at every study visit
• Patients answered questions about their level of disability with driving, lifting,

recreation, personal care, reading, sleeping, work, concentration, pain intensity, and headaches

• A score was calculated and recorded –

total possible points = 100 (higher scores indicated more disability)

• Mobi-C two-level patients demonstrated statistically significant better

disability improvement vs fusion patients at every study time point

Neck Disability Index (NDI) Through 5 Years

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Fusion RTW

(mean time – days)

Mobi-C RTW

(mean time – days)

Difference in Days

(favoring Mobi-C)

One-level study

36.8 29.3

7.5

Two-level study

66.8 45.9

20.9

Return to Work

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Number of days from surgery until patient was able to return to work

Mobi-C patients vs fusion, returned to work on average:

• 1 week faster (one-level patients)
• 3 weeks faster (two-level patients)

Efficacy of fusion decreases when the number of levels is increased from one to two, but Mobi-C effectiveness remains similar.

Overall Study Success

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Patients had to be successful in all 5 components to be considered an overall study success:

• Radiographic success, Neurologic success, NDI improvement, No

device-related events, No reoperations Fusion Patients Successful Mobi-C Patients Successful One-level study

65.3%

73.7%

Two-level study

37.4%

69.7%

Primary Composite Endpoint at 2 years

Study Conclusion Statistical superiority to fusion at two-levels

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Case Studies

34 Yr. Old Truck Driver

• Mr. R.A., a 34 year old truck driver involved in a motor vehicle

collision.

• Ongoing neck discomfort radiating into both upper extremities

involving the scapula, upper arm, and forearm with dysesthesia into both hands.

• Examination shows moderate paracervical muscle spasm and

limited neck movement with positive Spurling maneuver bilaterally and mild weakness in the infraspinatus and finger extensors bilaterally, worse on right.

• Patient failed to respond to 7 months of conservative care,

including analgesics, anti-inflammatories, oral corticosteroids and chiropractic treatment.

34 Yr. Old Truck Driver

34 Yr. Old Truck Driver

• The gentleman was taken to surgery for cervical arthroplasty

C5-6 with a partially sequestrated disc herniation centered to the right at C5-6, found with traumatic appearing rent in the anulus partially healed.

34 Yr Old Truck Driver

34 Yr Old Homemaker

• Ms. A.T., a 34 year old homemaker involved in a motor vehicle

collision when she was t-boned by another vehicle.

• Ongoing complaints of neck pain and left scapular and shoulder

pain radiating into the upper arm.

• On examination, no neurologic deficit, but positive Spurling

maneuver to the left and moderate paracervical muscle spasm and limitation of neck movement.

• Failed to respond to conservative care over 7 months, including

analgesics, anti-inflammatories, ice, heat, oral corticosteroids and ongoing chiropractic care.

34 Yr Old Homemaker

34 Yr Old Homemaker

• Patient was taken to surgery and found a partially healed

central anular rent and sequestration of disc material center to the left at C5-6 with encroachment of the left C6 nerve root.

34 Yr Old Homemaker

• Mr. S.D., a 46 year old counselor involved in a motor vehicle

collision in which she was rear-ended by a large truck with significant damage to her vehicle.

• Ongoing neck discomfort and occipital neuralgia headache with

radiation of pain into the left upper extremity extending as far as the forearm.

• Positive Spurling maneuver to the left with moderate

paracervical muscle spasm and some mild weakness in the left infraspinatus and biceps.

• Failed to respond to 5 months of conservative care, including

analgesics, anti-inflammatories, oral corticosteroids, marked modifications of activities, and continued chiropractic care.

46 Yr Old Counselor

46 Yr Old Counselor

46 Yr Old Counselor

• At surgery there was a diffuse disc protrusion at C5-6, C6-7 and

some sequestrated disc material in the foramen on the left at C6-7 with impingement of an edematous a erythematous left C7 nerve root in particular.

46 Yr Old Counselor

Questions?

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