Degeneration of the intervertebral discs causes many problems in the spine. Everything you do during the day while being upright tests your spine's ability to support your body weight. Minor injuries to a disc may occur and not cause pain at the time of the injury. These repeated daily stresses and minor injuries can add up over time and begin to affect the discs in your spine, which act like shock absorbers. The disc eventually begins to suffer from the wear and tear. It begins to degenerate.
A healthy intervertebral disc has a great deal of water in the nucleus pulposus (the center portion of the disc). The water content gives the nucleus a spongy quality and allows it to absorb spinal stress. Excessive pressure or injuries to the disc can cause damage to the annulus, which is the outer ring of tough ligament material that holds the vertebrae together.
The annulus is usually the first portion of a disc to be injured. Small tears show up in the ligament material of the annulus. When these tears heal, scar tissue develops. Scar tissue is not as strong as normal ligament tissue. The annulus becomes weaker over time as more scar tissue forms. This can lead to damage of the nucleus pulposus. It begins to lose its water content and dry up. View animation of degeneration.
Loss of water content causes the disc to lose some of its ability to act as a cushion. This can lead to even more stress on the annulus and still more tears as the cycle repeats itself. As the nucleus loses its water content, it collapses, allowing the two vertebrae above and below the disc to move closer to one another. This results in a narrowing of the disc space between the two vertebrae. As this shift occurs, the facet joints (located at the back of the spine) are forced to shift. Shifting changes the way the facet joints work together and can cause problems as well.
Bone spurs, sometimes called osteophytes, may begin to form around the disc space. These can also form around the facet joints. This is thought to be due to your body trying to stop the excess motion at the spinal segment. Bone spurs can become a problem if they start to grow into the spinal canal and press into the spinal cord and spinal nerves. This condition is called spinal stenosis.
The most common early symptom of degenerative disc disease is pain in the back that spreads to the buttocks and upper thighs. When doctors refer to degenerative disc disease, they are usually referring to a combination of problems in your spine that start with damage to the disc and eventually begin to affect all parts of your spine. Problems thought to arise from the degenerating disc itself include discogenic pain, and bulging discs.
Discogenic pain is a term back specialists use when referring to pain caused by a damaged intervertebral disc. A degenerating disc may cause mechanical (or structural) pain. As the disc begins to degenerate, there is some evidence that the disc itself becomes painful. Movements that place stress on the disc can result in back pain that appears to come from the disc. This is similar to any other body part that is injured, such as a broken bone or a cut in your skin. When these types of injuries are held still there is no pain, but if you move them they hurt.
Discogenic pain usually causes pain felt in your lower back. It may also feel like the pain is coming from your buttock area and even down into your upper thighs. The experience of feeling pain in an area away from the real cause is common in many areas of the body, not just your spine. For instance, a person with gallstones may feel pain in their shoulder, or a person experiencing a heart attack may feel pain in their left arm. This is referred to as radiation of the pain. It is very common for pain produced by spine problems to be felt in different areas of your body, including your back.
Bulging discs are fairly common in both young adults and older people. They are not cause for panic. Abnormalities, such as bulging or protruding discs, are seen at high rates on MRIs in patients both with and without back pain. Some discs most likely begin to bulge as a part of both the aging process and the degeneration process of the intervertebral disc. A bulging disc is not necessarily a sign that anything serious is happening to your spine.
A bulging disc only becomes serious when it bulges enough to cause narrowing of your spinal canal. If there are bone spurs present on the facet joints behind the bulging disc, the combination may cause narrowing of your spinal canal in that area. This is sometimes referred to as segmental spinal stenosis. View animation of bulging disc.
Before your doctor can diagnose your condition and design a treatment plan, a complete history and physical examare necessary. There are so many possible causes of pain. It is important to determine what is and is not at the root of your problem.
You may be asked to take a variety of diagnostic tests. The tests are chosen based upon what your doctor suspects is causing your pain. The most common diagnostic tests used to diagnose degenerative disc disease are ordinary X-rays and MRI scans. If your doctor suspects disc degeneration, X-rays can be used to verify a decrease in the height of space between vertebrae, bone spurs, facet hypertrophy (enlargement), and instability during flexion or extension of limbs. An MRI can verify loss of water in a disc, facet joint hypertrophy, stenosis, or a herniated disc.
Treatment for degenerative disc disease will depend on the seriousness of your condition. Some problems need immediate attention--possibly even surgery. The vast majority of back problems do not require surgery. Treatment for your back may be as simple as reassuring you that it is not a serious problem and doing nothing but watching and waiting. In most cases, simple therapies such as mild pain medications and rest are effective in relieving the immediate pain.
The overall goal of treatment for degenerative disc disease is to:
The more you know about how your back works and what you can do to prevent further injury, the more effective your program will be.
An epidural steroid injection (ESI) can be used to relieve the pain of stenosis and irritated nerve roots, as well as to decrease inflammation. Injections can also help reduce swelling from a bulging or herniated disc. Steroid injections are a combination of cortisone (a powerful anti-inflammatory steroid) and a local anesthetic that are given through your back into the epidural space. ESI is not always successful in relieving symptoms of inflammation. They are used only when conservative treatments have failed.