Degenerative Disc Disease is a gradual process that occurs as we age. Gradually the water and protein content of the body's cartilage changes. Sometimes this process is accelerated due to heavy occupational demands such as repetitive bending and twisting, heavy lifting, or accident and injury. These changes can result in weaker and thinner cartilage. Because both the discs and the joints (facet joints) are composed of cartilage, these areas are subject to wear and tear over time (degenerative changes). Spinal misalignment and/or injury can result in uneven wear and tear. This gradual deterioration of the discs between the vertebrae (back bones) is referred to as degenerative disc disease. These changes usually occur long before symptoms appear and before it can be identified on X-rays or other imaging techniques.
What is happening is the progression of wear and tear of the discs and the weakening of protein (collagen) of the outer band of the disc (annulus fibrosis) causing structural and biomechanical changes. At the same time, water and proteoglycan (PG) content also decreases. PGs are molecules that behave like super sponges and can bind and attract water hundreds of times their own molecular weight. “Disc desiccation” is a term used to describe the proteoglycan content decreasing and loss of water in the discs (dehydration). Often disc desiccation is among some of the terminology used to describe the condition of discs seen on MRI.
This process severely affects the "shock absorbing" ability of the discs as they "compress" under normal conditions. These changes usually occur simultaneously as the annulus fibrosis degenerates and generally leads to the disc’s inability to handle mechanical forces. Because the lumbar spine bears a majority of the body’s weight, degeneration of the disc tissue makes the disc more susceptible to herniation and can cause local pain in the affected area. Disc degeneration can sometimes lead to disorders such as spinal stenosis (narrowing of the spinal canal), spondylolisthesis (forward slippage of the disc and vertebra), and retrolisthesis (backward slippage of the disc and vertebra).
Although symptoms vary from person to person, most patients with lumbar degenerative disc disease will experience low-grade, continuous but tolerable pain that will occasionally flare (intensify) for a few days or more. Pain and other symptoms vary, but generally are:
Although degenerative disc disease is relatively common in aging adults, it seldom requires surgery. When medical intervention is necessary, the majority of patients respond well to non-operative forms of treatment like chiropractic manipulative therapy, physical therapy, or Non-Surgical Spinal Decompression therapy.
In this section we will discuss some of the confusion in the terminology regarding bulging discs, herniated discs, protruding discs, etc. Many times, even doctors use incorrect descriptive terms. We will use some diagrams to help demonstrate our lesson.
The following information is from the North American Spine Society, American Society of Spine Radiology, and American Society of Neuroradiology.
The term ‘bulging disc’ is and should be used as a descriptive term, not a diagnostic term.
Here is a bird’s eye view looking down onto a disc. Notice in the diagram the outer ring, this represents a
symmetrical bulging disc. The disc tissue is bulging out around the entire border of the vertebrae. This is a rare finding under MRI and CT scans.
Although ‘bulging disc’ is a popular term, it is usually not representative of what is really going on at the spinal level. It is used because it is easy to understand. The proper term that most people experience is a “herniated disc”.
This again is a broad category, which further breaks down into two more diagnostic terms. This is explained using the following diagrams:
These two diagrams are very accurate in the description (or diagnosis?) of disc herniations. You will commonly find these descriptive terms on your MRI or CT reports from your doctor.
By strict definition, a broad-based herniation involves between 25 and 50% of the disc circumference. A focal herniation involves less than 25% of the disc circumference.
Herniated discs may take the form of protrusion or extrusion based on the shape of the displaced or herniated material. The following diagram illustrates this well:
The previous information was provided to clarify the use of these terms. The simple fact is that if you have a herniated disc, the disc material can press on the nerve roots or central nerves running through the central canal where the spinal cord lives. This can produce serious back and radiating leg pain, as well as, numbness, tingling, and muscle weakness.
Occasionally, the injury and disruption in the annulus fibrosis can be the source of back pain. The outer 1/3 of the annulus fibrosis has a nerve supply, and if the center nuclear materials are migrating through the weakened annulus, this can cause pain.
This condition is sometimes referred to as internal disc disruption. This is very difficult to see on MRI or CT scans and is considered to be the early stages of a herniated disc, although it is still not visible on advanced imaging. This condition responds well to non-surgical spinal decompression, allowing blood, water, and nutrients to enter the disc and begin healing the damaged annulus fibrosis. Please see the diagram below.
This is a side view diagram. The left side is the front of the body and the right side is the back of the body.
Non-surgical spinal decompression can be very effective in treating these difficult conditions. The treatment results in an unloading of the offending disc structures, which in turn creates a negative pressure inside the disc.
This facilitates water and nutrient exchange into the disc, thus, allowing the injury to heal. It also can cause a vacuum-like effect, allowing the displaced materials to return to a more centralized position.
Over time, this treatment allows collagen, one of the body’s healing proteins, to form. Collagen can then
repair the cracks and fissures in the annulus fibrosis. In addition, the inner matrix material of the disc becomes healthier with the exchange of water and nutrients. Spinal stabilization rehab exercises should follow a common sense spinal decompression therapy program.