Degenerative Disc Disease

Back pain is a very common symptom and results in costs of billions of dollars annually for medical care and disability payments. Degenerative Disc Disease (DDD) is a term used to describe the normal changes that occur in the intervertebral spinal discs with aging or as a result of injury. DDD can occur at any level of the spine from the cervical spine(neck) to the sacral spine (sacrum).  DDD can refer to thinning discs, bulging discs, herniated discs or any combination of these conditions.

Vertebra and spinal nerves:

An intervertebral disc consists of the nucleus pulposus (a gelatinous mass) enclosed by the annulus fibrosis (a ring of fibrocartilaginous tissue). Intervertebral discs act as shock absorbers between the vertebrae protecting them from pressure.  Discs allow the spine to flex, bend, and twist.

With aging the discs in the spine lose fluid or dehydrate (desiccation), become thinner (loss of disc height), and become less flexible. As the space between the vertebrae narrows the spine becomes less stable. This causes the body to react by constructing bone spurs called osteophytes.

The intervertebral discs are thinner posteriorly (toward the back) than anteriorly (toward the front of the body). This can explain why there are more posterior than anterior bulging or herniated disc. When the outer layer of the disc cracks, the soft mass in the center may be forced out causing a bulging disc. If the outer layer tears open, the nucleus pulposus herniates (protrudes) outside of the disc into the central spinal canal or laterally to the right or to the left toward the foramen (the small opening through which the exiting nerve root passes). Herniated discs are also referred to as ruptured discs or slipped discs. Diagnosing DDD includes a medical history and physical examination. The diagnosis is confirmed with imaging studies such as x-rays, CT scans, and MRIs.

Bulging vs. Herniated Discs:

DDD has specific signs and symptoms associated with it. These signs and symptoms are specifically related to the level of the spine affected by the bulge or herniation. These symptoms can include severe back or neck pain, tenderness, numbness and tingling, weakness, or pain radiating down the arm or leg. On examination the straight leg raising test is positive, reflexes may be affected, and the range of motion of the neck or back is usually limited.

Bulging and herniated discs narrow the spinal canal or foramen causing compression of the spinal cord itself or the nerve roots coming off the spine. The result of nerve root compression or damage is called radiculopathy. The result of spinal cord damage is referred to as myelopathy. The spinal cord itself ends at the lower part of the thoracic spine. The nerve roots exiting the spine at lumbar and sacral levels come off the bottom of the spine like a horse’s tail(cauda equina). Pain secondary to nerve root compression tends to follow a specific distribution.

The most common levels of the cervical spine affected by DDD are C5-6 and C6-7. At these levels the C6 and C7 nerve roots exit the central spinal canal. When the C6 and C7 nerve roots are irritated, compressed, or impinged by herniated or bulging discs, an individual may experience neck pain, headaches, pain radiating down the arms into the hands, fingers and thumb, numbness and a tingling sensation, or muscle weakness. Reflexes in the arm may be diminished, also.  Even slight movement of the neck can cause increased pain.

In the lumbar spine 85% to 90% of the herniations occur at the L4-5 and L5-S1 levels affecting the L5 and S1 nerve roots. An impinged L5 nerve root causes low back pain. Pain and numbness may radiate to the foot and/or buttock on one or both sides. Weakness is noted in the great toe and in the ankle.  Foot drop is seen in cases of severe muscle weakness. Impingement of S1 nerve root can result in abnormal ankle reflexes and/or weakness with pain and numbness that radiates down to the sole or the outside of the foot, in addition to low back pain. With herniation or bulging of the lower lumbar disc sciatica may occur. The sciatic nerve is made up of five nerve roots.  Impingement, compression, or irritation of any of these five nerves can cause sciatica. Sciatica is generally described as sharp pain, burning sensation, numbness, or tingling that radiates or shoots from the lower back and upper buttock down the back of the thigh to the back of the leg. Severe sciatica can make walking difficult or even impossible.

Treatment for bulging and herniated discs usually begins with conservative, non-surgical interventions such as physical therapy or chiropractic manipulations, non-steroidal anti-inflammatory drugs (NSAIDS) or an oral steroid such as Prednisone, or a series of epidural steroid (cortisone) injections. If the pain and other symptoms fail to respond to conservative treatment, surgery may be performed. These procedures include, but are not limited to, microdiscectomy, discectomy, laminectomy, laminotomy, foraminotomy, and fusion with or without placement of plates and screws to stabilize the spine. These procedures are intended to take the pressure off the spine or nerve root (decompression) by removing the portion of the disc that is pressing on it, thus allowing the affected area to “heal”.  

A 95% success rate is expected from surgery for a herniated lumbar disc. However, about 10% of these individuals will have a recurrent disc herniation at the same level. A recurrence can happen within the first three months after surgery or years after surger

Social Security evaluates Degenerative Disc Disease under Listing 1.04. For further information please contact Mary Garrett, Director of Operations and Support Services at (800) 899-3433, on our Contact Us page, or through our Free Evaluation.