CERVICAL SPONDYLOSIS

CERVICAL SPONDYLOSIS

Background

Cervical spondylosis is a chronic degenerative condition of the cervical spine that affects the vertebral bodies and intervertebral disks of the neck (in the form of, for example, disk herniation and spur formation), as well as the contents of the spinal canal (nerve roots and/or spinal cord). Some authors also include the degenerative changes in the facet joints, longitudinal ligaments, and ligamentum flavum. (See also Cervical Spondylosis: Diagnosis and Management, Spinal Stenosis [in the Neurosurgery section], and Spinal Stenosis [in the Orthopedic Surgery section.)

Spondylosis progresses with age and often develops at multiple interspaces. Chronic cervical degeneration is the most common cause of progressive spinal cord and nerve root compression. Spondylotic changes can result in stenosis of the spinal canal, lateral recess, and foramina. Spinal canal stenosis can lead to myelopathy, whereas the latter 2 can cause radiculopathy.

Pathophysiology

Intervertebral disks lose hydration and elasticity with age, and these losses lead to cracks and fissures. The surrounding ligaments also lose their elastic properties and develop traction spurs. The disk subsequently collapses as a result of biomechanical incompetence, causing the annulus to bulge outward. As the disk space narrows, the annulus bulges, and the facets override. This change, in turn, increases motion at that spinal segment and further hastens the damage to the disk. Annulus fissures and herniation may occur. Acute disk herniation may complicate chronic spondylotic changes.

As the annulus bulges, the cross-sectional area of the canal is narrowed. This effect may be accentuated by hypertrophy of the facet joints (posteriorly) and of the ligamentum flavum, which becomes thick with age. Neck extension causes the ligaments to fold inward, reducing the anteroposterior (AP) diameter of the spinal canal.

As disk degeneration occurs, the uncinate process overrides and hypertrophies, compromising the ventrolateral portion of the foramen. Likewise, facet hypertrophy decreases the dorsolateral aspect of the foramen. This change contributes to the radiculopathy that is associated with cervical spondylosis. Marginal osteophytes begin to develop. Additional stresses, such as trauma or long-term heavy use, may exacerbate this process. These osteophytes stabilize the vertebral bodies adjacent to the level of the degenerating disk and increase the weight-bearing surface of the vertebral endplates. The result is decreased effective force on each of these structures.

Degeneration of the joint surfaces and ligaments decreases motion and can act as a limiting mechanism against further deterioration. Thickening and ossification of the posterior longitudinal ligament (OPLL) also decreases the diameter of the canal.

The blood supply of the spinal cord is an important anatomic factor in the pathophysiology. Radicular arteries in the dural sleeves tolerate compression and repetitive minor trauma poorly. The spinal cord and canal size also are factors. A congenitally narrow canal does not necessarily predispose a person to myelopathy, but symptomatic disease rarely develops in individuals with a canal that is larger than 13 mm.

Frequency

United States

Cervical spondylosis is a common condition that is estimated to account for 2% of all hospital admissions. It is the most frequent cause of spinal cord dysfunction in patients older than 55 years. On the basis of radiologic findings, 90% of men older than 50 years and 90% of women older than 60 years have evidence of degenerative changes in the cervical spine.

International

Investigators in a study involving Ghanaians reported, "out of 225 patients who carried loads on their head, 143 (63.6%) had cervical spondylosis, and of the 80 people who did not carry load on their head, 29 (36%) had cervical spondylosis."

Mortality/Morbidity

• The course of cervical spondylosis may be slow and prolonged, and patients may either remain asymptomatic or have mild cervical pain.
• Long periods of nonprogressive disability are typical, and in a few cases, the patient's condition progressively deteriorates.
• Morbidity ranges from chronic neck pain, radicular pain, diminished cervical range of motion (ROM), headache, myelopathy leading to weakness, and impaired fine motor coordination to quadriparesis and/or sphincteric dysfunction (eg, difficulty with bowel or bladder control) in advanced cases. The patient may eventually become chair-bound or bedridden.

Race

No apparent correlation between race and cervical spondylosis exists.

Sex

Both sexes are affected equally. Cervical spondylosis usually starts earlier in men than in women.

Age

• Symptoms of cervical spondylosis may appear in persons as young as 30 years but are found most commonly in individuals aged 40-60 years. Radiologic spondylotic changes increase with patient age; 70% of asymptomatic persons older than 70 years have some form of degenerative change in the cervical spine. See also Frequency.
• Cervical spondylosis usually starts earlier in men than in women.
• When cervical spondylosis develops in a young individual, it is almost always secondary to a predisposing abnormality in 1 of the joints between the cervical vertebrae, probably as a result of previous mild trauma.

History

Common clinical syndromes associated with cervical spondylosis include the following:

• Cervical pain
• Chronic suboccipital headache may be present. Mechanisms include direct nerve compression; degenerative disk, joint, or ligamentous lesions; and segmental instability.
• Pain can be perceived locally, or it may radiate to the occiput, shoulder, scapula, or arm.
• The pain, which is worse when the patient is in certain positions, can interfere with sleep.
• Cervical radiculopathy
• Compression of the cervical nerve roots leads to ischemic changes that cause sensory dysfunction (eg, radicular pain) and/or motor dysfunction (eg, weakness). Radiculopathy most commonly occurs in persons aged 40-50 years.
• An acute herniated disk or chronic spondylotic changes can cause cervical radiculopathy and/or myelopathy.
• The C6 root is the most commonly affected one because of the predominant degeneration at the C5-C6 interspace; the next most common sites are at C7 and C5.
• Most cases of cervical radiculopathy resolve with conservative management; few require surgical intervention.
• Cervical myelopathy
• Cervical spondylotic myelopathy is the most serious consequence of cervical intervertebral disk degeneration, especially when it is associated with a narrow cervical vertebral canal.
• Cervical myelopathy has an insidious onset, which typically becomes apparent in persons aged 50-60 years. Complete reversal is rare once myelopathy occurs.
• Involvement of the sphincters is unusual at presentation, as based on the patient's perception of symptoms.
• Five categories of cervical spondylotic myelopathy are described; these are based on the predominant neurologic findings, as follows:
• Transverse lesion syndrome - Corticospinal and spinothalamic tracts, as well as the posterior columns, are involved.
• Motor syndrome - This primarily involves the corticospinal or anterior horn cells.
• Central cord syndrome - Motor and sensory involvement is greater in the upper extremities than the lower extremities. (See also Central Cord Syndrome.)
• Brown-Séquard syndrome - Unilateral cord lesion with ipsilateral corticospinal tract involvement and contralateral analgesia are present below the level of the lesion. (See also Brown-Sequard Syndrome, in the Physical Medicine and Rehabilitation section, and Brown-Sequard Syndrome, in the Emergency Medicine section.)
• Brachialgia and cord syndrome - Predominant upper limb pain is present, with some associated long-tract involvement.
• Less common manifestations
• Primary sensory loss may be present in a glovelike distribution.
• Tandem spinal stenosis is a simultaneous cervical and lumbar stenosis resulting from spondylosis. It is a triad of findings: neurogenic claudication, complex gait abnormality, and a mixed pattern of upper and lower motor neuron signs.
• Dysphagia may be present if the spurs are large enough to compress the esophagus.
• Vertebrobasilar insufficiency and vertigo may be observed.
• Elevated hemidiaphragm, caused by spondylotic compression of C3-4 (as noted in a case report), may be another finding.

Physical

Findings at physical examination may include the following:

• Spurling sign - Radicular pain is exacerbated by extension and lateral bending of the neck toward the side of the lesion, causing additional foraminal compromise.
• Lhermitte sign - This generalized electrical shock sensation is associated with neck extension.
• Hoffman sign - Reflex contraction of the thumb and index finger occurs in response to nipping of the middle finger. This sign is evidence of an upper motor neuron lesion. A Hoffman sign may be insignificant if present bilaterally.
• Distal weakness
• Decreased ROM in the cervical spine, especially with neck extension
• Hand clumsiness
• Loss of sensation
• Increased reflexes in the lower extremities and in the upper extremities below the level of the lesion
• A characteristically broad-based, stooped, and spastic gait
• Extensor planter reflex in severe myelopathy

Causes

• Age
• Cervical spondylosis is a disease observed most commonly in elderly individuals.
• Among persons younger than 40 years, 25% have degenerative disk disease (DDD), and 4% have foraminal stenosis, as confirmed with magnetic resonance imaging (MRI).
• In persons older than 40 years, almost 60% have DDD, and 20% have foraminal stenosis, as confirmed with MRI.
• Trauma
• The role of trauma in spondylosis is controversial.
• Repetitive, subclinical trauma probably influences the onset and rate of progression of spondylosis.
• Work activity - Cervical spondylosis is significantly higher in patients who carry loads on their head than in those who do not (see Frequency).
• Genetics
• The role of genetics is unclear.
• Patients older than 50 years who have normal cervical spine radiographic findings are significantly more likely to have a sibling with normal or mildly abnormal radiographic results.

Lab Studies

• Usually, no specific findings are present.
• Other findings may include those related to an underlying etiologic or pathogenetic disorder that initiates the spondylotic changes.

Imaging Studies

• Plain cervical radiography is routine in every patient with suspected cervical spondylosis.
• This examination is valuable in evaluating the uncovertebral and facet joints, the foramen, intervertebral disk spaces, and osteophyte formation.
• In select circumstances, flexion-extension views may be needed to detect instability.
• Myelography, with computed tomography (CT) scanning, is usually the imaging test of choice to assess spinal and foraminal stenosis.¹
• Because myelography method is invasive, most physicians depend on MRI in diagnosing cervical spondylosis.¹
• Myelography adds anatomic information in evaluating spondylosis.
• Myelography may be especially useful in visualizing the nerve root takeoff.
• CT scanning, with or without intrathecal dye, can be used to estimate the diameter of the canal.
• CT scans may demonstrate small, lateral osteophytes and calcific opacities in the middle of the vertebral body.
• MRI is a considerable advance in the use of imaging to diagnose cervical spondylosis. It offers the following advantages:
• Direct imaging in multiple planes
• Better definition of neural elements
• Increased accuracy in evaluating intrinsic spinal cord diseases
• Noninvasiveness
• Myelogramlike images
• High–signal-intensity lesions can be seen on magnetic resonance images of spinal cord compression; this finding indicates a poor prognosis.

Other Tests

• Electromyography is useful in evaluating radiculopathy caused by spondylosis, but it may have only limited value in assessing myelopathy.
• In myelopathy, somatosensory evoked potential (SSEP) responses are delayed or have a low amplitude.²
• Cortical motor evoked potentials (MEP) may be more sensitive than SSEPs in evaluating spinal cord dysfunction.³
• As an invasive procedure, cervical diskography is not commonly used in the evaluation of cervical spondylosis.
• Urodynamic studies may be helpful in evaluating bladder incontinence (see Other Treatment).

Histologic Findings

Thinning and fragmentation of the articular cartilage may be observed. The normal smooth, white articular surface becomes irregular and yellow. Continued loss of articular cartilage leads to exposure of areas of subchondral bone, which appear as shiny foci on the articular surface (eburnation). Fibrosis, increased bone formation, and cystic changes frequently occur in the underlying bone. Loss of articular cartilage stimulates new bone formation, usually in the form of nodules (osteophytes) at the bone edges.

Rehabilitation Program

Physical Therapy

• Immobilization of the cervical spine is the mainstay of conservative treatment for patients with cervical spondylosis. Immobilization limits the motion of the neck, thereby reducing nerve irritation. Soft cervical collars are recommended for daytime use only, but they are unable to appreciably limit the motion of the cervical spine. More rigid orthoses (eg, Philadelphia collar, Minerva body jacket) can significantly immobilize the cervical spine (see Special Concerns). The patient's tolerance and compliance are considerations when any of the braces are used. A program of isometric cervical exercises may help to limit the loss of muscle tone that results from the use of more restrictive orthoses. Molded cervical pillows can better align the spine during sleep and provide symptomatic relief for some patients.
• Mechanical traction is a widely used technique. This form of treatment may be useful because it promotes immobilization of the cervical region and widens the foraminal openings. However, traction in the treatment of cervical pain was not better than placebo in 2 randomized groups.
• The use of cervical exercises has been advocated in patients with cervical spondylosis. Isometric exercises are often beneficial to maintain the strength of the neck muscles. Neck and upper back stretching exercises, as well as light aerobic activities, also are recommended. The exercise programs are best initiated and monitored by a physical therapist.
• Passive modalities generally involve the application of heat to the tissues in the cervical region, either by means of superficial devices (eg, moist-heat packs) or mechanisms for deep-heat transfer (eg, ultrasound, diathermy).
• Manual therapy, such as massage, mobilization, and manipulation, may provide further relief for patients with cervical spondylosis. Mobilization is performed by a physical therapist and is characterized by the application of gentle pressure within or at the limits of normal motion, with the goal of increasing the ROM. Manual traction may be better tolerated than mechanical traction in some patients. Manipulation is characterized by a high-velocity thrust, which is often delivered at or near the limit of the ROM. The intention is to increase articular mobility or to realign the spine. Contraindications to manipulative therapy include myelopathy, severe degenerative changes, fracture or dislocation, infection, malignancy, ligamentous instability, and vertebrobasilar insufficiency.

Occupational Therapy

Patients with upper extremity weakness often lose their ability to perform activities of daily living (ADL), vocational activities, or recreational activities. Lifestyle modifications may involve an evaluation of workplace ergonomics, postural training, neck-school therapy (supervised, small-group therapy), stress management, and vocational assistance. Disability can be improved with specific strengthening exercises of the upper extremities, special splinting to compensate for weakness, and the use of assistive devices that allow the patient to perform previously impossible activities.

Recreational Therapy

The recreational therapist can use recreational and community activity to accomplish the following:

• Help the patient maintain his/her physical strength, social skills, and motivation
• Assist the patient and family in adjusting to the disability
• Decrease the patient's atypical behaviors
• Increase the patient's independence
• Reinforce other therapies
• Provide community integration
• Further evaluate the level of functioning in cases of severe disability caused by cervical spondylosis

Medical Issues/Complications

Cervical spondylosis may result in complications (see Mortality/Morbidity), including the following:

• Cervical myelopathy
• Paraplegia
• Tetraplegia
• Recurrent chest infection
• Pressure sores
• Recurrent urinary tract infection

Surgical Intervention

• Indications for surgery include the following:
• Progressive neurologic deficits
• Documented compression of the cervical nerve root and/or spinal cord
• Intractable pain
• The aims of surgery are to relieve pain and neuronal structured compression, as well as, in select cases, to achieve stabilization.
• Approaches for surgery are anterior or posterior. (See also the articles Role of Corpectomy in Cervical Spondylosis and Anterior Decompression for Cervical Spondylosis Associated With an Early Form of Cervical Ossification of the Posterior Longitudinal Ligament, on Medscape.)
• Anterior approaches include the following:
• Diskectomy without bone graft
• Diskectomy with bone graft
• Cervical instrumentation
• Posterior approaches include the following^{4, 5}:
• Decompressive laminectomy and foraminotomy
• Hemilaminectomy
• Laminoplasty⁶

Consultations

Consultations with the following specialists may be helpful:

• Psychologist or psychiatrist
• Neurologist
• Neurosurgeon and/or orthopedic spinal surgeon
• Urologist
• Internist
• Occupational therapist
• Physical therapist
• Recreational therapist
• Social worker

Other Treatment

• Injection - Cervical, zygapophyseal, intra-articular steroid injection can be helpful for active synovitis. The facet injections can be diagnostic and therapeutic. Mechanical facet pain is better evaluated with facet joint nerve blocks. Long-term relief can often be accomplished with a rhizotomy procedure. Cervical epidural block might be beneficial in cervical spondylosis, especially if an inflammatory component is present. Epidural and selective nerve root blocks can be diagnostically and therapeutically helpful in cases of radiculopathy. Trigger-point injections may be helpful.
• Treatment of bowel and bladder dysfunction - Some patients with bowel dysfunction may benefit from a daily suppository, enema, or oral laxative. The administration should be followed by digital stimulation so that the patient's defecation occurs at a predictable time. Evaluate bladder incontinence with urodynamic studies. Pharmacologic intervention is possible in some patients, but many individuals need an intermittent catheterization program and control of fluid intake. An indwelling catheter is occasionally required if the patient does not have the dexterity to comply with a catheter program.
• Rehabilitative nursing - A nurse should be involved in the educational process regarding the development of an effective bowel and/or bladder program and the prevention of pressure sores.
• Psychosocial support - Patients with significant disability often react with fear, anxiety, or depression. Referral to a psychologist or psychiatrist for psychotherapy, pharmacotherapy, and/or family counseling may be indicated.

Further Inpatient Care

• In general, patients with uncomplicated cervical spondylosis and mild disability can be followed up on an outpatient basis.
• Patients with severe disability are better examined in the hospital.

Further Outpatient Care

• Obtaining a thorough history and physical examination is required to assess the following:
• Status of the cervical spine
• Function of the genitourinary, musculoskeletal, gastrointestinal, vascular, respiratory, and integumentary systems
• Nutritional, psychological, and vocational aspects of independent living and healthy living habits
• Laboratory studies may be indicated.
• Tests can be used to determine the patient's overall state of health and the complete blood picture.
• Urinalysis and an assessment of renal function may be performed.
• Physical therapy is recommended (see Physical Therapy).
• Occupational therapy is often beneficial (see Occupational Therapy).
• The following specialists may be consulted as needed:
• Social worker
• Psychologist
• Recreational therapist
• Orthopedist
• Neurologist or neurosurgeon
• Urologist
• Internist

In/Out Patient Meds

• Medications may include the following:
• NSAIDs - Acetylsalicylic acid, naproxen, ibuprofen, indomethacin, mefenamic acid, piroxicam
• Corticosteroids - Oral prednisone or single IM injection
• Muscle relaxants - Cyclobenzaprine, methocarbamol, and baclofen
• Narcotic agents
• Antidepressants - Doxepin, amitriptyline

Transfer

• The patient may need to be transferred or referred to a facility in which the following specialists are available:
• Occupational therapist - The therapist can help to modify the patient's home or work environment. Early referral is indicated to minimize deconditioning caused by further immobility or inactivity.
• Physical therapist
• Neurosurgeon
• Recreational therapist
• Psychologist

Deterrence

• Patients may apply the following measures to help prevent cervical spondylosis or its complications:
• Avoid high-impact exercise (eg, running, jumping).
• Maintain cervical ROM with daily ROM exercise.
• Maintain neck muscle strength, especially neck extensor strength.
• Avoid holding the head in 1 position for a long period (for example, while driving or watching TV).
• Avoid prolonged neck extension.
• Be careful when performing physical activities that are done infrequently; such activities can trigger a flare in symptoms.
• If the patient has only morning stiffness, a long, hot shower every morning may help.
• Cervical spondylosis is difficult to prevent because it is a part of the normal aging process. Individuals may reduce their risk by maintaining good neck strength and flexibility along with leading an active and healthy lifestyle. Preventing neck injuries (eg, using proper equipment in contact sports, headrest and seatbelt use in automobiles) also may reduce the risk of developing this condition.

Complications

• Cervical spondylotic myelopathy, the most serious consequence
• Cervical myelopathy; can cause disabilities, which are categorized as follows:
• Grade 0 - Root signs and symptoms, with no evidence of cord involvement, are observed.
• Grade I - Signs of cord involvement are present, but the patient's gait is normal.
• Grade II - Mild gait involvement is present, and the patient may be employed.
• Grade III - Gait abnormality prevents the patient's employment.
• Grade IV - Ambulation is possible only with assistance.
• Grade V - The patient is chair-bound or bedridden.
• Paraplegia
• Tetraplegia
• Recurrent chest infection
• Pressure sores

Prognosis

• Cervical spondylosis is a slowly progressive, chronic joint disability, especially when it is associated with neuronal compression.
• Cervical spondylotic myelopathy is the most serious consequence.
• High–signal-intensity lesions can be seen on magnetic resonance images of spinal cord compression; this finding indicates a poor prognosis.

Patient Education

• For excellent patient education resources, visit eMedicine's Back, Ribs, Neck, and Head Center. Also, see eMedicine's patient education article Shoulder and Neck Pain.

Medical/Legal Pitfalls

• Medical pitfalls
• Use of a bed that is too hard
• Overuse of muscle relaxants or pain medications
• Prolonged rest, inactivity, or vigorous exercise
• Overreliance on imaging studies
• Failure to recognize depression
• Failure to recognize sleep disturbance
• Failure to recognize chronic pain syndrome
• Legal pitfalls
• The role of trauma in cervical spondylosis is controversial, especially in today's medicolegal climate.
• In particular, worker's compensation and accidental injury cases may revolve around issues related to cervical spondylosis.

Special Concerns

• Use and abuse of cervical orthotics
• One of the most useful cervical orthotic devices for cervical spondylosis is the soft collar. Although it does not actually prevent neck motion, it serves as a reminder to immobilize the neck.
• Cervical orthotic devices are inexpensive and do not interfere with carotid or vertebral circulation.
• Cervical orthotic devices should usually be used only for short periods.
• The center of a cervical orthotic device is wider than the ends. The collar should be worn so that the narrow portion is anterior. This positioning helps to make neck extension (which worsens spondylosis) difficult, while still permitting flexion.
• Surgical intervention - The decision to pursue surgical intervention should be made with caution, especially in advanced cases with myelopathy. The surgical outcome may be unsatisfactory, and the patient and his/her relatives should be made aware of the expected benefits of surgery.⁷