Degeneration of the intervertebral discs is a normal part of aging. However, in some patients, disc degeneration occurs early or more severely than is “normal.” In some cases, the degeneration of the intervertebral discs can lead to severe, chronic pain.
Degenerative disc disease can manifest as various symptoms. It is a common misconception that only the elderly are affected by DDD. However, this is not the case; DDD can affect younger individuals as a result of injury or other variables. In many patients suffering from degenerative disc disease, the pain is reported as a “pins and needles” type of sensation. The pain can be exacerbated by daily activities such as sitting down, bending, or reaching. Any dull, aching pain that is localized in the lower back requires the attention of a physician at the soonest available time. In the event that an appointment isn’t immediately available, DDD patients often experience relief when they lay down in the prone or supine positions. This position alleviates some of the pressure from the spine and may provide temporary relief.
What causes DDD?
The vertebral discs are made up of two “types” of tissue. The outer ring of the disc is a fibrous, tougher material called the annulus fibrosus. The inner portion of the disc is a “jelly-like” texture and is called the nucleus pulposus. Daily activities, such as walking, standing, sitting, and other activities, put pressure on the discs and cause them to compress. The onset of DDD is described as the time when the discs begin to weaken, either from normal aging or injury. Degenerative disc disease occurs as a result of the following processes:
- Disc wall tears: a small tear in the outer ring of the disk (annulus fibrosus) that causes pain.
- Disc wall heals: injury to the spine can cause disc wall tears that, over time, heal and develop scar tissue. The scar tissue that forms isn’t as strong as the original tissue, and weakens the wall of the discs. Repeated injury can create more tears, more scar tissue, and more pain. Eventually, the disc is serverely weakened and compromised.
- Disc center weakening: decreased water content in the nucleus pulposus. Over time, the compression of the spine, normal aging, and/or injury causes the nucleus of the disc to lose it’s “jelly-like” character as it loses water content. When the nucleus becomes less hydrated, it is less able to act as a shock absorber for the spine. This causes pain.
- Nucleus collapses: the nucleus loses its ability to adequately absorb the shock of impact on the spine and collapses. The vertebrae above and below the spine are forced closer together, which alters the alignment of the spine, and causes the facet joints (where vertbral bones touch) to move into an unfavorable position.
- Bone spurs: growths and abnormalities that form as a result of unfavorable positioning of the vertebrae. When spurs grow into the spinal canal, they can affect the spinal cord and nearby nerves; this is a condition called spinal stenosis.