Definition

• a combination of degenerative disc disease & osteophyte formation
• typically begins at age 40-50
• seen in men > women
• most common occurs at C6-7 > C5-6 levels
• risk factors include frequent lifting, smoking & driving
• may lead to myelopathy, radiculopathy, or both

Pathoanatomy

Osteophytosis

• bony spurs or ridges - osteophytes
• occurs as result of breakdown in the annular fibers of annulus fibrosus
• disk material stretching & displacing these fibers, causing stress at ligamentous attachments leading to formation of osteophytes
• osteophytes initially extend horizontally, later on vertically from edges of vertebra, sometimes bridging disk space
• involves the disc, two facet joints & two false uncovertebral joints(Lushka)
• cervical cord becomes impinged when diameter of canal (normally about 17 mm) reduced to less than 13 mm

Hyperextension

• cord & roots are pinched between discs and adjacent osteophytes anteriorly, and hypertrophic facets and infolded ligamentum flavum posteriorly

Hyperflexion

• cord narrows & the neural structures are tethered anteriorly across discs or spondylitic bars

Radiculopathy

• spondylotic changes in the foramina primarily from chondro-osseous spurs of the joints of Luschka may restrict motion and may lead to nerve root compression

Disk herniation

• usually posterolateral, between posterior edge of uncinate process & lateral edge of posterior longitudinal ligament
• resulting in acute radiculopathy

Myelopathy

• central herniation
• spondylotic bars with a congenitally narrow canal

Apophyseal joints

• show early irregularity & blurring of the joint surfaces
• joint space narrowing & eventual spurring & sclerosis
• lateral & oblique view
• allows evaluation of facet joints
• determine if osteophytes of apophyseal joints project medially into foramina canal
• osteophytes arising from the ventral portion of superior articular process may cause symptomatic foraminal narrowing
• rarely osteophytes may project anteriorly and impinge upon vertebral artery, resulting in arterial insufficiency
• loss of disk height leads to reduced neuroforaminal volume –> root more susceptible to compression

Joints of Luschka

• symphysis type of articulation between vertebral bodies
• joints give rise to bony spurs - as can main facet joints & edges of vertebral bodies
• exiting N root on each side travels between these joints, & can be compressed by osteophytes extending into intervertebral foramen from any or all three of sources

Differential Dg.

• Stroke / TIA
• Multiple sclerosis
• Thoracic outlet sy.
• Pancoast Tumors
• RSD
• Brachial neuritis (upper & lower motor neurons, sensation is N)
• Spinal cord tumour
• Syringomyelia
• Cerebral hemisphere lesion
• Low pressure hydrocephalus
• Herpes Zoster
• Shoulder impingement, RC tears
• AS, Reiter’s dx. or DISH
• occurance of bony ankylosis found in spodylosis involve only 1 or 2 levels

Clinical

Signs and Symptoms

Pain

• early symptom
• funicular pain
• characterized by central burning & stinging
• Lhermitte’s phenomenon - lightening like sensations down back with neck flexion
• may be ischaemic in origin

Myelopathy

• characterized by weakness (upper > lower extremity)
• ataxic, broad based, shuffling gait
• sensory changes
• rarely urinary retention
• myelopathy hand
• finger escape sign (LF spontaneously abducts d/t weak intrinsics)

Radiculopathy

• can be associated with myelopathy
• can involve one or multiple roots
• symptoms include neck, shoulder & arm pain, paresthesias & numbness
• findings may overlap - intraneural intersegmental connections of sensory roots
• lower nerve root at a given level is usually affected
• 70% by spondylosis (with or without disk protrusion)
• soft disc protrusion causes radiculopathy in only 20–25% of patients
• C7 radiculopathy is most common followed by C6 radiculopathy

Spurling’s Manouever

• mechanical stress, such as excessive vertebral motion, may exacerbate symptoms
• neck hyperextension with head tilted toward the affected side will narrow the size of the neuroforamen and may exacerbate the symptoms or produce radiculopathy

Shoulder Abduction Relief Test:

• significant relief of arm pain with shoulder abD, elbow flexion, hand on top of head
• this sign is more likely to be present with soft disc herniation
• test is likely to be negative with radiculopathy caused by spondylosis (osteophyte compression)

Neurological examination

Upper Cord Involvement: (cervical radiculopathy / myelopathy)

Cervical Disc Herniation

• most frequent at C6-7 level, but occur at C5-6 & to a lesser extent at C4-5 & other levels
• in relatively younger persons soft disk protrusion is more common than hard disk protrusion

Types of herniation

• intraforaminal herniation
• most common type
• cause predominately sensory changes
• posterolateral type
• occurs near entrance zone of foramen
• causes predominately motor changes
• central type
• disc herniation occurs more to the midline (ie posterior herniation)
• compresses spinal cord in addition to, or instead of the nerve root
• results in cervical myelopathy

Symptoms

Pain

• neck pain from nerve root compression
• radiating into ipsilateral upper extremity with paresthesias, numbness, or weakness
• may be intensified by neck movement, especially by extension or by lateral flexion to side of herniation, & by coughing or straining

Exam

• limitation of neck extension
• Spurling’s sign
• shoulder abduction relief test
• lower motor neuron dysfunction
• muscle weakness & hypotonia
• reduction of deep tendon reflexes at level of cord compression
• upper motor neuron dysfunction
• spasticity, clonus
• increased deep tendon reflexes
• Babinski’s sign
• reduction of sensation below level
• loss of erection, bladder, & bowel function

Cervical Myelopathy

• characterized by weakness (upper > lower extremity)
• ataxic broad based shuffling gait, sensory changes;
• rarely urinary retention

Anatomy of compression

• anterior cord compression - protruding disc or posterior osteophytes
• anterolateral compression - joints of Luschka
• lateral compression - cervical facets
• posterior compression - ligamentum flavum

Clinical Findings

• UMN findings such as hyper-reflexia, clonus, or Babinski’s sign
• funicular pain, characterized by central burning and stinging
• Lhermitte’s phenomenon
• radiating lightening like sensations down back with neck flexion

Jaw jerk

• performed by the tapping on the slightly opened jaw - controlled by the fifth cranial nerve
• a normal reflex contraction of the masseter effectively rules out pathology above the foramen magnum

Upper extremity

• mixed upper and lower motor neuron findings
• can present with hand dysfunction with loss of fine motor function such as writing

Myelopathy hand

• finger escape sign - small finger spontaneously abducts d/t weak intrinsics

Inverted radial reflex (C5 - C6)

• may be present when cord & root compression are present at C5 level
• demonstrated by tapping brachioradialis tendon
• diminished reflex noted along with a reflex contraction of spastic finger flexors
• d/t peripheral compression of C6 nerve root (from disc or spur) which allows UMN reflex to occur

Biceps reflex

• primarily indicates neurologic integrity of C5
• the reflex also has a C6 component

Lower extremity

• UMN signs
• hyper-reflexia & frank clonus in lower extremities;
• decline in ability to walk, apparent ataxia
• loss of lower extremity proprioception

Lhermitte’s sign

• paresthesias or leg weakness exacerbated by neck flexion
• shock-like sensation
• men may be cursed by this as they attempt to urinate

Prognosis

• condition has high potential for becoming worse leading to severe disability
• myelopathic symptoms have variable potential for recovery, but prognosis for recovery is better when decompression is performed early

Radiographs

Lateral & oblique views

• loss of disk height, with subsequent loss of cervical lordosis
• vacuum phenomena
• indicates spondylosis
• erosive changes in the disk & end plates more suggestive of inflammatory lesions
• anterior osteophytes
• largest
• may alter the overall shape of the vertebral body
• large anterior osteophytes may be suggestive of DISH
• posterior osteophytes
• smaller
• more important clinically –> project into spinal canal
• stenosis
• in upright erect lateral view at distance of 6 feet, distance from posterior cortex of vertebral body at its midpoint to laminar line should be approximately 17 mm (SAC)
• if this distance is narrowed by posterior osteophyte, diameter of 13 mm should begin to raise suspicion of impingement of spinal canal, & diameters of < 10 mm correlate highly w/ cord compression

Flexion-extension views

• AP subluxation of more than 3.5 mm
• more than 20 deg of saggital angulation

EMG

• studies have a high false negative rate
• may be helpful in select cases for differentiating peripheral nerve lesions from more central compression & disease such as AML

MRI

• with subtle clinical & x-ray findings consider dynamic MRI (flexion-extension)
• spinal cord may show increased signal changes on T2 images

CT - Myelogram

• to localise lesion
• compression ratio: smallest AP diameter divided by largest transverse diameter

Treatment

Conservative Rx

• rest
• collar or braces
• traction (Halter) controversial
• analgesia, NSAIDs
• physio

Surgical

Indications

• intractable pain - failure of conservative Rx
• increasing neurological deficit
• myelopathy

Anterior approach & fusion

• requires discectomy, removal of posterior osteophytes & removal of bony sclerotic bed of vertebral body
• fusion of one or more levels is performed by countersinking iliac crest bone graft between vertebral bodies
• Cloward
• Smith-Robinson
• stability of bone graft is achieved by initial distraction of soft tissues as graft is inserted
• once, distractive force is removed the graft will be held firmly between vertebral bodies
• may use instrumentation - plates
• note: to maintain stability the posterior longitudinal ligament should be left intact, if possible
• in most cases of cervical spondylosis involving one or two levels, the pathology will be anterior and will be reflecting clinically as myelopathy, anterior cord syndrome, or central cord sy.
• when the primary pathology is mostly anterior, generally the anterior approach should be anterior
• the one exception to this may be the rheumatoid C-spine

Posterior approach

• posterior decompression thru’ a hemi-laminectomy
• smaller operation that takes less time and does not require a bone graft
• most indicated for far-lateral disc herniation
• removal of the spinous process & lamina on each side at multiple levels;
• facet joints
• resection of > 25 % of facet can result in cervical instability –> posterior fusion should be done