Osteoarthritis, Neck Pain, and Spinal Cord Compression

A discussion of Cervical Spondylotic Myelopathy

Photo by Sebastian Merkelmann (iStockphoto)

While the hip and knee joints are by far the most common places effected by osteoarthritis, the same disease process can affect any joint in the body. Since the spine is has the highest concentration of joints in any one place (there are 3 joints per level, and 24 spinal levels), it is not surprising that arthritic changes of the spine are quite common. Arthritis of the cervical spine, which is composed of the 7 segments of the spine that are in the neck, is quite common.

Many describe the wear and tear of the joints in the cervical spine as a natural part of the aging process.

Dr. Boden and colleagues performed a study of healthy people without neck pain, and looked for how many of them had MRI evidence of cervical spine arthritis (also known as spondylosis). It turned out that 25% of people under the age of 40, and almost 60% of people over the age of 40 had MRI evidence of arthritis in their cervical spine. It is important to remember that all of these were people without neck pain. A similar study by Matsumoto and colleagues confirmed these findings, and showed that over 90% of people average age 50 without any neck pain had arthritic changes in their cervical spine. When followed over 10 years 81% had showed worsening degenerative changes (indicating progressive arthritis) on MRI.

What this tells us that arthritic changes in the cervical spine on MRI are in essence a variation of normal, and by themselves are not a problem.

A small subset of the people that have these changes on MRI, will actually have symptoms such as neck pain, as well as symptoms from compression of the nerve roots or the spinal cord. One of the issues that can develop in spines that are heavily affected by arthritis is subsequent compression of the spinal cord.

The medical term for this condition when it occurs in the neck is Cervical Spondylotic Myelopathy (CSM).

In order to understand this problem we must first have a brief review of the anatomy of the cervical spine. The cervical spine is made of 7 segments or ‘levels’. Each segment has a vertebral body in the front, connected to a bony arch called the lamina, which surrounds the spinal canal. Each vertebral body is connected to the one above and the one below by two tough ligaments called the anterior and posterior longitudinal ligaments. The lamina are also connected to the ones above and below by a similar ligament called the ligamentum flavum.

Degenerative or arthritic changes in the spine cause bony spurs in the cervical spine, as well as calcium deposits in the 3 ligaments described, and changes in alignment of the spine. These three issues can change the shape of the spinal canal. Any process that makes the spinal canal smaller has the potential to lead to pinching of the spinal cord.

When the spinal cord is pinched, this condition is called “myelopathy”. Thus, the term cervical spondylotic myelopathy refers to arthritic changes of the cervical spine that cause pinching of the spinal cord.

Symptoms of CSM can be variable but include neck pain, numbness of the hands, difficulty with coordinated movements of the hands/fingers such as buttoning a shirt, writing, or using keyboards, as well as poor balance and difficulty walking. Tendon reflexes when tested by a physician may also be abnormal. The next important question is what happens over time to people with CSM? Current research suggests that somewhere between 20% and 60% of people with CSM progress to having worsening symptoms. For this reason CSM is commonly thought of as a disorder that is typically treated by surgery in order to stabilize neurologic function and prevent further decline. The timing of surgery is unclear, and no data is available to guide the decision of how long to wait for surgical intervention.

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