Degenerative = relating to deterioration over time*
Disc = one of the disk-shaped cushions between the bones of the spinal cord
Disease = a specific problem with a body or body part
* (Note that the word “degenerative” in “degenerative disc disease” doesn’t mean that the pain will keep getting worse over time. That is, the “disease” itself is not degenerative. Instead, “degenerative” describes the cause of the changes in the spinal discs. The changes in the spinal discs are due to wear and tear over time—not to trauma, infection, or some other cause.)
The vertebral column (backbone) is made up of 33 vertebrae. These vertebrae are grouped into divisions called the cervical (neck), thoracic (upper back), and lumbar (lower back). Each pair of vertebrae are connected by an intervertebral disc–a fibrous disc with a softer cartilage core. In a healthy spine, these intervertebral discs cushion the vertebrae and permit normal flexibility of the spine.
As people age, however, the discs undergo changes. They may dry out, thin, or crack. The soft cartilage core may bulge or herniate out through the fibrous outer portion of the disc. Degenerative disc disease is an umbrella term that describes these age-related processes.
Most people’s spinal discs degenerate over time. By the age of 35, approximately 30% of people will show evidence of disc degeneration at one or more levels. By the age of 60, more than 90% of people will show evidence of some disc degeneration. Degeneration itself is normal, and does not necessarily cause pain. Painless degeneration is just called degeneration. The term “degenerative disc disease” describes disc degeneration that causes pain and other symptoms.
Degenerative disc disease can cause pain, weakness or numbness. Exact symptoms vary depending on the location and type of disc degeneration. However, the primary symptoms of degenerative disc disease include sharp and/or chronic pain in the back and neck.
As the discs undergo change, the body may react and develop bony growths called bone spurs. In severe cases, these bone spurs may take up room needed by the spinal cord and surrounding nerves to move freely in the spinal canal. If the nerves in the spine become compressed (pinched), patients may experience weakness in the arms or legs and numbness in the legs. Compression of the spinal cord itself is referred to as myelopathy. A patient with myelopathy may have difficulty walking, and may even experience loss of bladder and bowel control.
Causes and Risk Factors
Degenerative disc disease is usually associated with the normal effects of aging. The discs between the bones of the spine are made up of cartilage, fibrous tissue, and water. With age, these discs can weaken and may flatten, bulge, or break down.
Tests and Diagnosis
If a patient presents with symptoms associated with degenerative disc disease, the surgeon may order the following tests:
- X-rays – although X-rays cannot show soft tissue like discs, they provide details of the bone structures in the spine.
- Magnetic resonance (MR) imaging – this type of scan provides a detailed image of discs, allowing surgeons to see how the nerves and spinal canal space are affected by degenerative disc disease.
- Computed tomography (CT) scan – provides a detailed image of bone structures in the spine and is a great option for those patients who cannot undergo MR scans (for example, those who have a pacemaker or who have specific types of metallic implants)
Treatment for degenerative disc disease will depend on the severity of the condition. In most cases, the problem is not severe enough to require surgery. Before considering surgery as an option, the doctor may initiate any of the following nonoperative measures:
- heat and/or ice therapy
- activity modification
- oral pain and/or steroid medications
- physical therapy (with the focus of strengthening the muscles of the back/neck and improving flexibility and range of motion)
- epidural injections of steroids or pain medication
For the most part, these nonoperative measures are effective in providing pain relief.
However, surgery may be required for some patients, including those
- who have not responded to nonoperative measures
- who have an identified structural abnormality that can be effectively corrected
- whose disc changes have resulted in spinal cord compression. (In these cases, patients usually experience nerve deficits and/or loss of bladder and bowel control.)
- with chronic severe pain
The surgeon may perform a discectomy to remove the disc and associated bone spurs that are compressing the spinal cord and or surrounding nerves. Removing the damaged disc makes room for the spinal cord and surrounding nerves to move freely in the spinal canal. As a result, the pressure that was once on the spinal cord is relieved.
In some cases, the spine will become unstable after the damaged disc is removed. In these cases, the surgeon may perform an instrumented spinal fusion to maintain spinal stability. In this procedure, metallic devices are used to stabilize the spine, and then bone taken from another part of the body or from a bone bank is implanted to encourage bone to grow across the span.
The majority of patients who undergo surgery at The Spine Hospital at the Neurological Institute of New York see an improvement in their condition with help from one of our experienced doctors. The results of surgery usually are excellent and most patients return to normal function in a matter of weeks.