Cervical spondylosis is a disorder caused by abnormal wear on
the cartilage and bones of the neck (cervical vertebrae) with degeneration and mineral
deposits in the cushions between the vertebrae (cervical disks). Cervical
spondylosis results from chronic degeneration of the cervical spine including the cushions
between the neck vertebrae (cervical disks) and joints between the bones of the cervical
spine. There may be abnormal growths or "spurs" on the vertebrae (the bones of
These accumulated changes caused by degeneration can gradually compress one or more of the
nerve roots. This can lead to increasing pain in the neck and arm, weakness, and changes
in sensation. In advanced cases, the spinal cord becomes involved. This can affect not
just the arms, but the legs as well.
A previous neck injury (which may have occurred several years prior) can predispose to
spondylosis, but the major risk factor is aging. By age 60, 70% of women and 85% of men
show changes consistent with cervical spondylosis on X-ray.
Description of Cervical Spondylosis
As it runs from the brain down the back, the spinal cord is protected by ring like
bones, called vertebrae, stacked one upon the other. The vertebrae are not in direct
contact with one another, however. The intervening spaces are filled with structures
called disks. The disks are made up of a tough, fibrous outer tissue with an inner core of
elastic or gel-like tissue.
One of the most important functions of disks is protecting the vertebrae and the nerves
and blood vessels between the vertebrae. The disks also lend flexibility to the spinal
cord, facilitating movements such as turning the head or bending the neck. As people age,
disks gradually become tougher and more unyielding. Disks also shrink with age, which
reduces the amount of padding between the vertebrae.
As the amount of padding shrinks, the spine loses stability. The vertebrae react by
constructing osteophytes, commonly known as bone spurs. There are seven vertebrae in the
neck; development of osteophytes on these bones is sometimes called cervical
osteoarthritis. Osteophytes may help to stabilize the degenerating backbone and help
protect the spinal cord.
By age 50, 25-50% of people develop cervical spondylosis; by 75 years of age, it is
seen in at least 70% of people. Although shrunken vertebral disks, osteophyte growth, and
other changes in their cervical spine may exist, many of these people never develop
However, about 50% of people over age 50 experience neck pain and stiffness due to
cervical spondylosis. Of these people, 25-40% have at least one episode of cervical
radiculopathy, a condition that arises when osteophytes compress nerves between the
vertebrae. Another potential problem occurs if osteophytes, degenerating disks, or
shifting vertebrae narrow the spinal canal. This pressure compresses the spinal cord and
its blood vessels, causing cervical spondylitic myelopathy, a disorder in which large
segments of the spinal cord are damaged. This disorder affects fewer than 5% of people
with cervical spondylosis. Symptoms of both cervical spondylitic myelopathy and cervical
radiculopathy may be present in some people.
Prevention of Cervical Spondylosis
Since cervical spondylosis is part of the normal aging process, not much can be done to
prevent it. It may be possible to ward off some or all of the symptoms by engaging in
regular physical exercise and limiting occupational or recreational activities that place
pressure on the head, neck, and shoulders. The best exercises for the health of the
cervical spine are noncontact activities, such as swimming, walking, or yoga. Once
symptoms have already developed, the emphasis is on symptom management rather than
Information for this article was compiled from the National
Institutes of Health.