Cervical Spondylosis
Definition
Pathoanatomy
Hyperextension
Hyperflexion
Radiculopathy
Disk herniation
Myelopathy
Apophyseal joints
Joints of Luschka
Differential Dg.
Clinical
Spurling's Manouever
Shoulder Abduction Relief Test:
Neurological examination
Cervical Disc Herniation
Types of herniation
Symptoms
Exam
Cervical Myelopathy
Anatomy of compression
Clinical Findings
Jaw jerk
Upper extremity
Myelopathy hand
Inverted radial reflex (C5 - C6)
Biceps reflex
Lower extremity
Lhermitte's sign
Prognosis
Radiographs
Flexion-extension views
EMG
MRI
CT - Myelogram
Treatment
Surgical
Posterior approach
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
- 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 spaces
- 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)
C5 | C6 | C7 | C8 | T1 | |
---|---|---|---|---|---|
Sens: | Lat.arm | Thumb, IF | Mid f. | RF, LF | Med.arm |
Motor: | Deltoid | Wrtist ext. | Triceps,FCR | Finger Flex | Interossei |
5/5 | 5/5 | 5/5 | 5/5 | 5/5 | |
Disc: | C4-C5 | C5-C6 | C6-C7 | C7-T1 | T1-T2 |
Reflex: | Biceps | Brachiorad./td> | Triceps | None | None |
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/li>
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
Indications
- 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