Cervical Spondylosis

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 the spine).

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 significant problems.

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 prevention.

Information for this article was compiled from the National Institutes of Health.