eMedicine Specialties > Physical Medicine and Rehabilitation > Cervical Spine Disorders

Cervical Spondylosis

Author: Hassan Ahmad Hassan Al-Shatoury, MD, PhD, MHPE,, Associate Professor, Department of Neurosurgery, Suez Canal University; Co-Director, Center of Research and Development in Medical Education and Health Services Suez Canal University Hospital
Coauthor(s): Ayman Ali Galhom, MD, PhD, Lecturer (Associated Professor), Department of Neurosurgery, Suez Canal University Faculty of Medicine, Egypt
Contributor Information and Disclosures

Updated: Apr 24, 2009

Introduction

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.

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. (See image below and Image 3)

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. (See images below and Images 1-2, 4-5.) The result is decreased effective force on each of these structures.

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.

Evidence from a 2009 report indicated that cervical spondylosis with myelopathy was the most common primary diagnosis (36%) among elderly US patients admitted to the hospital for surgical treatment of a degenerative cervical spine between 1992 and 2005.⁴ The study, which looked at 156,820 hospital admissions for elderly Medicare beneficiaries, also determined that fusion was the most common procedure (70%) performed in these patients for cervical spine degeneration, with 58% of the fusions being anterior.

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.

Clinical

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. (See images below and Images 4-5.)

• 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. (See image below and Image 2.)

• 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.)⁵
  • 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.

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