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CERVICAL DISC DISORDER
LUNCH HOUR CME15/12/2010
Spondylosis: any or various degenerative diseases of the spine
Myelopathy: any disease or disorder of the spinal cord or bone marrow
Radicular: of, relating to, or involving a nerve root Radiculopathy: any pathological condition at the
nerve roots.
Definitions of Spinal Disorders
Cervical spondylosis Cervical radiculopathy Cervical myelopathy
A non-specific term Refers to any lesion of cervical spine of a
degenerative nature (non-inflammatory disc degeneration)
Cervical Spondylosis
Imbalance between formation & degradation of proteoglycans & collagen in disc
With aging, a -ve imbalance with subsequent loss of disc material -> degenerative changes
Factors influencing severity of degeneration◦Heredity◦Trauma◦Metabolic◦Other environmental effects, eg. smoking
Pathology
Degeneration ->◦Disc herniation◦Stenosis◦ Instability
Spine unable to withstand physiologic loads -> significant risk for neurologic injury, progressive deformity & long-term pain & disability
Not common in cervical spondylosis except those with stiffness in middle & lower segments who develop compensatory hypermobility at C3-4 or C4-5 -> myelopathy
Cervical spinal instability◦Radiographic criteria of White
>11o angulation >3.5 mm translation of adjacent subaxial segments
Most people with degenerative changes of the cervical spine remain asymptomatic.
Symptomatic patients are usually older than 40 years of age and present with symptoms that are caused by the compression of neural structures.
There are three main symptom complexes related to cervical spondylosis:
1.Neck pain2.Cervical radiculopathy3.Cervical myelopathy
Presentation
X-rays changes◦Narrowing of intervertebral disc◦Sclerosis of endplates◦Osteophyte formation
Similar changes may occur in facet joints Most frequently in C5-6 & C6-7 Incidence of spondylosis on X-rays in
asymptomatic patients◦80% in 51-60 age group◦95% in 61-70 age group
Radiological findings
Incidence of Spondylosis on MRI in asymptomatic patients
<40 yr >40yr
Cervical disc herniation
10% 5%
Degenerative disc changes
25% 60%
Cervical stenosis 4% 20%
A condition caused by compression of a nerve root in cervical spine.
Involves a specific spinal level with sparing of levels immediately above & below.
Peak age:50-54 year Disc protrusion =22% spondylosis=68% 41% had associated lumbar radiculopathy
Cervical Radiculopathy
C7 monoradiculopathy-most common,C6-7 level. Pain post. aspect of arm, posterolateral
forearm,middle finger Tricep and fingers extensor weakness Tricep reflex reduce. 90% not treated surgically were asymptomatic.
Cervical Radiculopathy
C3 radiculopathy-involving C2C3 disk. Uncommon Sensory-post.neck,suboccipital and ear No detectable muscle motor. C4 radiculopathy-neck and shoulder pain No significant motor deficit. Radiating pain-base
of the neck,midshoulder and scapula. No reflex changes.
Radiculopathy
C5 :deltoid muscle- difficulty in elevating of arm. Weakness of supraspinatus-infraspinatus Decrease bicep reflex C6:herniation bt.C5C6. top of neck,along the
bicep into lat. Aspect of the forearm and onto dorsal surface of hand between thumb and index finger.
Bicep and brachoradialis reflex decrease.
C8 radiculopathy-numbness small finger and medial half of the ring finger.
Most of intrinsic muscles of the hand. Lose fine fingertip and grip strength.
Largely secondary to mechanical compression of nerve roots.
5 articulations:1. intervertebral disc2. 2 uncovertebral3. 2 facets joints
Patho-anatomy
Innervation of the cervical intervertebral disc
ST=cervical sympathetic trunk
VA=vertebral artery; ALL=anterior longitudinal
ligament PLL=posterior
longitudinal ligament SVN=cervical sinuvertebral nerve
Half of adult population will experience neck and radicular pain.
Rarely progressed to myelopathic state (Less and Turner, 1963)
Natural history
Varies greatly-Pain, paraesthesia and weakness. Classically:significant radicular pain and refered
trapezial and periscapular pain. Only 55% had pain in a strictly radicular pattern.
(Henderson et al,1983,neurosurgery). Other studies:60%-70% motor weakness,70%
reflex changes. Often described symptoms that correlate with
various head position.
Clinical features
Exacerbation with neck hyperextension and tilted toward affected side.
Modified spurling test(combination of head extension and head tilt)
Shoulder abduction relief sign-specific for soft disc herniation.
Symptoms and examination
Acute-disc herniation:Posterolateral, mid-line and intra-foraminal
Insidious-degenerative Uncovertebral-compress nerve root anteriorly. Neuroforaminal narrowing by:osteophytes
superior facet, decrease disc height
Cervical disc herniation and degenerative spondylosis
o Three locations of focal disc protrusions:
(A) intraforaminal; (B) posterolateral; (C) midline
1. Cervical myelopathy2. Entrapment syndrome3. Thoracic outlet syndrome4. Intraspinal and extraspinal tumor
Differential diagnosis
X ray-instability and pathologic changes◦ Flexion-extension lateral films-instability◦ Loss of disc space height◦ Foraminal osteophytes◦Kyphosis◦Subluxution◦Posterior compression from facet arthropathy
CT-to evaluate transverse foramina, size and shape of spinal canal, facet and uncovetebral joints
MRI-spinal canal diameter, spinal cord, IVD and vetebral ligaments.
Imaging
Non-operative:1. Soft collar-<2 weeks2. Traction(24 degree flexion)- release pressure,
increase blood flow3. Heat and cold therapy4. Medical- opioid, Nsaids, antispasmodic
Management
Indications: significant pain or deficits after 6 weeks or progressive neurologic deficits
Approach should be determined by position & type of lesion◦Soft lateral discs easily removed by posterior approach◦Spurs & more paramedian discs via anterior approach
Surgical procedures
Options:• Anterior cervical discectomy & fusion• Anterior foraminotomy (Jho’s procedure)• Posterior foraminotomy• Cervical arthroplasty.
For unilateral osteophytes, facet hypertrophy, extruded disc causing unilateral radiculopathy
Avoids bone fusion but often does not efficiently eliminate the herniated disc materials
Posterior cervical foraminotomy
Indications for this approach:• Progressive or persistent symptoms arising from
unilateral or bilateral lateral disc herniations • Spondylotic neural foraminal compromise at one
to two levels. Sacrifice the spinal motion at the herniated disc
level. C/I-congenital stenosis, stenosis arising
predominantly from posterior structures, and disease at greater than three levels
ANTERIOR CERVICAL DISCECTOMY AND FUSION
provides an effective elimination of the compressing herniated portion of the disc or bone spurs, while preserving the remaining disc between the vertebrae and maintaining spinal motion
Anterior cervical microforaminotomy (Jho procedure)
Myelopathy = Cord dysfunction Cervical Spondylitic Myelopathy (CSM) introduced
by Brain et. al. 1952. CSM= gait abnormality and weakness or stiffness
of the legs which usually develop insidiously. > 50% CM are CSM. Other causes for myelopathy are trauma, tumour
and congenital.
Cervical Myelopathy
1.Developmental stenosis: AP diameter of spinal canal of 12 mm or less .
2.Dynamic stenosis: defined as Penning’s jaw diameter - distance from posterior inferior corner of vertebral body, to anterior margin of subjacent lamina, 12 mm or less, a/w 2 mm of retrolisthesis with neck in extension
3.Disc herniation4.Segmental OPLL (Ossification of posterior longitudinal ligament)5.Continuous OPLL6.Posterior spur7.Calcification of ligamentum flavum (CLF): tends to occur in elderly
women1 & 2 most common
Pathology
Cervical Myelopathy (Static stenosis)
Pain usually absent. Discomfort varies from aching to sharp pain.Gait disturbances,clumsy hands, spasticity,sphincter disturbances, motor weakness.
Cervical Myelopathy
The proximal motor groups of the legs are more
involved than the distal groups (which is the
opposite of the pattern with lumbar stenosis)
Clinical Presentation
Hyperreflexia, positive Hoffmann’s sign, Babinski test,
clonus, sensory and motor changes.
Myelopathic hand syndrome:
thenar atrophy, positive finger escape sign and grip
release test.
Positive Lhermitte’s sign: electric shock sensation with
neck flexion
Physical findings
Many patients have evidence of significant compression on neuroradiologic imaging but are relatively asymptomatic
No patient ever return to normal state. 75% episodic worsening. 20% slow and steady progression. 5% rapid onset with lengthy disability. Myelopathy rarely developed in patient with spondylosis. Generally, once moderate signs and symptoms of
myelopathy develop,the ultimate prognosis is poor.
Cervical Myelopathy:natural history
Scapulohumeral reflex. (tap on scapula spine-pathology above C4)
L’Hermitte’s sign. (flexion on neck Paresthesia / shock down to extremities)
Babinski sign.
Cervical Myelopathy(signs)
Plain X-ray for stenosis◦ Normal = ~17 mm◦ Absolute (AP canal diameter <10
mm) or relative (10-13 mm) stenosis are risk factors for myelopathy, radiculopathy, or both
◦ Pavlov's ratio (canal/vertebral body width) Should be 1.0, with <0.85
indicating stenosis Ratio of <0.80 is a significant risk
factor for lateral neurologic injury This identifies a congenitally
narrow canal◦ OPLL
MRI
◦Shows cervical disc prolapse well
◦Demonstrates spinal cord well
◦High intensity signal can be found in spinal cord on T2,
representing myelomalacia (necrosis/cavity formation) CT shows OPLL & bone spurs best
Cervical Myelopathy(evaluation)
Brown-Sequard syndrome. Unilateral cord lesion.◦Cross motor and sensory
dysfunction.
Cervical Myelopathy(clinical syndromes)
Central cord syndrome.◦ Typically Upper limbs are
more affected than lower limbs.
Cervical Myelopathy(clinical syndromes)
Motor system syndrome. Anterior cord syndrome.◦Spinal thalamic tract.◦Cortical spinal tract.◦Minimal sensory complaints.
Cervical Myelopathy(clinical syndromes)
Transverse lesion syndrome. Posterior cord syndrome◦Posterior Column.◦Spinal thalamic tract.◦Cortical spinal tract.◦Anterior horn cells often involved.
Cervical Myelopathy(clinical syndromes)
Mild myelopathy:o May display findings such as slight gait
disturbance and mild hyper-reflexia but may have no functional deficits and no weakness.
o Re-evaluation every 6 to 12 months to look for deterioration of neurologic function or a change in symptoms.
Non-operative treatment
Muscle relaxants Analgesics NSAID Physiotherapy Cervical support
Conservative management
◦Absolute indication = neurological deficit which is progressing
◦Patients with cord compression on MRI but no objective symptoms or findings of myelopathy best treated non-operatively
Herniation shows better improvement after surgery, older patients & those with dynamic stenosis show less improvement.
Indications for surgery
Surgical approaches◦No controlled prospective studies comparing anterior &
posterior approaches◦Approach depends on
Location of pathology Levels of involvement Stability of spine Presence of kyphotic deformity
◦ Indications: Generally recommended if disc herniation
or posterior spur causing compression at 1 or 2 levels
Also indicated if there is kyphotic deformity, so that correction can be achieved
◦ Options: Anterior discectomy & interbody fusion
with anterior spinal instrumentation With more extensive anterior
decompression involving excision of osteophytes - discectomy & corpectomy with strut graft fusion
Anterior Decompression & Fusion
◦Ant. Corpectomy strut grafting better decompression kyphotic deformity more problem if >3 level
Operative management
◦ Generally recommended if there is compression of spinal cord at 3 levels or more, in developmental stenosis or calcification of ligamentum flavum
◦ Options Laminoplasty
Directly decompresses cord posteriorly & indirectly decompresses cord anteriorly
Requirements Straight or lordotic cervical spine Stable spine Multilevel cord compression
o Laminectomy - poor outcome due to spinal instability & kyphosis
Posterior decompression +/- fusion
◦Canal expansive laminoplasty decompression of spinal canal with reduced risk for kyphotic
deformity No fusion Z-plasty (Hattori) Hemi-lateral open (Hirabayashi) Bilateral open (Kurokawa)
Operative management
Operative management
Operative management
< 7 = severe 8-12 = moderate 13-16 mild Max = 17
Cervical Myelopathy(evaluation)
Complications◦Anterior surgery
anterior structures (dysphagia, hoarseness, vocal cord, sore throat, sympathetic chain)
non union. Graft slippage (1% -2% ACDF) (6% - 29% graft)
◦Posterior surgery kyphosis (preservation of posterior structures) reduced ROM with laminoplasty
◦General complication infection (< 1%) hematoma and compression cord injury
Positive prognostic value include larger transverse area of the cord.
Younger patient age Shorter duration of symptoms, and Single rather than multiple levels of involvement
Symptoms > 6 months Canal : body ratio < 0.8 Compression ratio < 0.4 after surgery.
Cervical Myelopathy;bad prognosis