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All About Orthopedics, 5th Annual ConferenceSeptember 25th, 2020

Chase C. Woodward, MD, MPHOrthopedic Spine Surgeon

Degenerative Cervical Myelopathy• Spinal cord compression due to age-related cervical stenosis

• Most common cause of spinal cord impairment in the elderly

• Symptoms: insidious but progressive functional decline Gait dysfunction Difficulty with fine motor tasks Balance problems Numbness to the limbs Bladder dysfunction

• Diagnosis is often delayed

• Surgical treatment is effective

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Pathoanatomy-Intervertebral Disc

Desiccation and collapse

Bulging/herniation/extrusion

-Bone and JointsOsteophytosis and remodeling

Capsule hypertrophy

-LigamentsHypertrophy and redundancy

Ossification

-Segmental InstabilityAntero- or retro-listhesis

Degenerative Cervical Myelopathy

OPLL: ossified posterior longitudinal ligament. OLF: ossified ligamentum flavum.

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Epidemiology and Genetics• Incidence likely underestimated

Common disorder of elderly, surgical rates rising Based on non-traumatic spinal cord injuries

• Incidence: 41 per million people• Prevalence: 605 per million people

Based on hospitalizations• Incidence: 4.04 per 100,000 person years

• Risk Factors:Age, tobacco use, diabetes, occupational/athletic loading

• Genetics: relative risk 5.21 in first-degree relativesCollagen IX, vitamin D receptor, MMPs, apolipoprotein E

Clinical PresentationA protean disease with no pathognomonic findingsOne general rule: onset is insidious• Gait dysfunction – #1 reason for presentation• Imbalance• Clumsiness • Hand weakness and intrinsic atrophy• Axial or radicular pain• Limb stiffness/spasticity• Glove numbness and proprioceptive loss• Urinary urgency, frequency or hesitation

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Physical Exam FindingsMotorAtaxic gaitWeak grip and intrinsicsAtrophy of handsSpasticity

ReflexesHyperreflexiaHoffman’s signInverted radial reflexSustained clonusBabinkski sign

SensoryGlove-like numbness to handsProprioceptive dysfunction

Special testsRomberg testTandem gaitGrip-and-release testLhermitte sign

Physical Exam Findings

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Physical Exam Findings

Physical Exam Findings

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Imaging• Radiographs

– Evaluate cervical alignment and degenerative changes• MRI

– Gold standard– Usually without contrast– Specific anatomy– Visualize spinal cord

T2 “Myelomalacia” T1 hypo-intensity

• CT +/- myelogram– If MRI is contraindicated– To evaluate for ossified PLL

Imaging• Radiographs

– Evaluate cervical alignment and degenerative changes• MRI

– Gold standard– Usually without contrast– Specific anatomy– Visualize spinal cord

T2 “Myelomalacia” T1 hypo-intensity

• CT +/- myelogram– If MRI is contraindicated– To evaluate for ossified PLL

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Functional Scales

Nurick Grades

Japanese Orthopedic Association

Measurement tools to judge severity of disease and response to treatment

Mild myelopathy JOA > 15Moderate myelopathy JOA 12-14Severe myelopathy JOA < 11

Differential Diagnosis• Amyotrophic lateral sclerosis (ALS)

Significant overlap in age and symptoms Distinguishing features:

• Presence of fasciculations • Absence of sensory deficits

• Guillain-Barré Syndrome Hyporeflexia, can involve cranial nerves

• Multiple Sclerosis Usually younger patients, can involve cranial nerves

• Normal Pressure Hydrocephalus Cognitive dysfunction, gait apraxia

• Others: stroke, tumors, B12 deficiency, neuropathies

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Natural History• Infamously variable and unpredictable• Classically (1956 Clark and Robinson):

Described three patterns of progression:• Stepwise deterioration (majority)• Slow and steady deterioration• Rapid onset of symptoms, but then stable (few)

• Modern perspective (meta-analysis): Variably progressive disease

• Stepwise decline with periods of quiescence 20-62% of patient deteriorate during follow-up (mJOA)

Management OptionsReferral to spine surgeon for consultation

Observation: Counsel on symptoms of myelopathy Regular clinical follow-up Physical therapy for conditioning Possible immobilization or analgesia Discourage high risk activities

Surgery: Decompression of the spinal cord Multiple fusion and fusionless techniques

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Clinical Practice Guidelines Severe myelopathy

– Surgical intervention

Moderate myelopathy– Surgical intervention

Mild myelopathy– Surgical intervention OR supervised trial of rehabilitation– If symptoms worsen or fail to improve → Surgical interven on

Non-myelopathic with cord compression on imaging– Counsel patients on symptoms and follow clinically

Non-myelopathic with cord compression + radiculopathy– Surgical intervention OR supervised trial of rehabilitation– If symptoms worsen or fail to improve → Surgical interven on

2017

Severe myelopathy JOA < 11Moderate myelopathy JOA 12-14Mild myelopathy JOA > 15

Patients with moderate to severe myelopathyUnderwent surgical decompression

Improvement in Japanese Orthopedic Association (JOA) score after surgery

JOA

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Patients with moderate to severe myelopathyUnderwent surgical decompression

Improvement in Nurick Grade after surgery

Nurick Grade

Patients with moderate to severe myelopathyAll underwent surgical decompression

Improvement in Visual Analog Scale for Pain after surgery

VAS Pain

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Choosing Surgical Techniques

• Anterior approach– Anterior decompression and fusion– Cervical disc arthroplasty

• Posterior approach– Laminectomy and fusion– Laminoplasty

• Combined anterior + posterior approach

Anterior Decompression and Fusion• Advantages:

– Less painful, muscle splitting dissection– Fusion allows for extensive decompression– Restores cervical lordosis

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Anterior Decompression and Fusion

Anterior Decompression and Fusion• Advantages:

– Less painful, muscle splitting dissection– Fusion allows for extensive decompression– Restores cervical lordosis

C6 corpectomy and fusion

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Cervical Disc Arthroplasty

• AdvantagesLess painful, muscle splitting dissectionMotion preserving“Fusionless” anterior approach

Posterior Laminectomy and Fusion• Advantages

– Extensile approach to access many levels– Fusion offers durable result, may address axial pain

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Posterior Laminectomy and Fusion

Laminoplasty• Advantages

– Extensile posterior approach to access multiple levels– Motion preserving– “Fusionless” posterior approach

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Laminoplasty

Drilling the “open side”

Laminoplasty

Drilling the “hinge side”

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LaminoplastyOpening the “door”

Combined Anterior-Posterior• Advantages

– Addresses both anterior and posterior pathology– “Reconstruction” of deformity– Increased stability

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Complication Cumulative incidence

Axial neck pain 5.6%

Dysphagia 2.2%

Instrument or graft complication 2.0%

C5 palsy 1.9%

Pseudarthrosis (non-union) 1.8%

Infection 1.5%

Cumulative incidence of complications 14.1%

SummaryDegenerative Cervical Myelopathy

– Common cause of spinal cord dysfunction in elderly– Insidious onset, symptoms are progressive– Diagnosis based on careful history + exam + imaging– Referral to a spine surgeon is appropriate– Management strategy

• Mild disease → careful rehabilita on vs surgery• Moderate to severe disease → surgery preferred

– Surgery improves patient outcomes– Surgical approach is tailored to the patient

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Sources

Akter F, Kotter M. Neurosurg Clin N Am 2018;29:13-19.

Badhiwala JH, Wilson JR. Neurosurg Clin N Am 2018;29:21-32.

Bakhsheshian J, Mehta VA, Liu JC. Global Spine J 2017;7:572-586.

Cason GW, Anderson III ER, Herkowitz HN. The evaluation and treatment of cervical radiculopathy and myelopathy. In: Rao RD, ed. Orthopaedic Knowledge Update: Spine. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2012:293-304.

Fehlings MG, Tetreault LA, Riew KD, et al. Global Spine J 2017;7:21S-27S.

Fehlings MG, Tetreault LA, Kurpad S, et al. Global Spine J 2017;7:53S-69S.

Nouri A, Tetreault L, Singh A, et al. Spine (Phila Pa 1976) 2015;40:E675-E693.

Rhee JM, Shamji MF, Erwin WM, et al. Spine (Phila Pa 1976) 2013;38:S55-S67.

Tetreault L, Palubiski LM, Kryshtalskuj M, et al. Neurosurg Clin N Am 2018;29:115-127.

THANK YOU

Chase C. Woodward, M.D., M.P.H.Orthopedic Spine Surgeon

September 25th, 2020

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