DISC EXTRUSION

March 11, 2021 Nicholas Lancaster

Disc Extrusion – Understanding Your Condition

If you have been diagnosed with a disc extrusion, the first thing you should know is that you are far from alone. Millions of people from all walks of life develop the condition, which also is known as a herniated disc. It is a degenerative spine condition, which means it is often associated with the effects of aging on the anatomy of the spine.

However, you should not take this to mean that only seniors are susceptible to disc extrusions. The fact is, a disc extrusion can occur at almost any stage of adult life. Naturally, you are more likely to develop a disc extrusion if you are 50 or older. After all, by that time of life, the spinal anatomy has been exposed to a great deal of wear and tear. However, conditions that affect the intervertebral discs are as dependent on other factors such as overuse, obesity, and inherited traits as they are on the age of the patient.

Of course, knowing that you have plenty of company when it comes to this condition does nothing to alleviate the pain and other symptoms sometimes caused by the leakage of inner disc material into the spinal canal. Still, the fact that the condition is as prevalent as it is means there is a lot of information available about its causes, risk factors, symptoms, and treatment. And anyone who has the condition will naturally want to know as much as possible about it in order to make an informed decision about how to handle it. A thorough understanding of a disc extrusion begins with a brief explanation of the various components of the spinal anatomy, particularly those related to the development of a herniated disc.

The Anatomy of a Disc Extrusion

In terms of a disc extrusion, the most significant element of the spinal anatomy is the intervertebral disc. However, before delving deeper into these sponge-like wedges that serve as the spine’s shock absorbers, it’s important to understand the anatomy of the spine from top to bottom. Here is a brief description of the spine’s major components:

Vertebrae – There are 33 or 34 of these segmented bony structures, which are stacked vertically from the base of the skull to the tailbone. The top seven vertebrae are located in the neck and are known as the cervical vertebrae. The next 12 are in the middle back and are called the thoracic vertebrae. The next five are in the lower back and are called the lumbar vertebrae (some people have six lumbar vertebrae). Below that are the vertebrae of the sacrum (pelvis) and the coccyx (tailbone), which are fused.

Spinal cord/nerve roots – The spinal cord is an elongated bundle of nerves that descends off the brain stem and runs vertically through the middle of the spine to the top of the lumbar region. At each vertebral level, nerve roots branch off the spinal cord, transmitting sensory and motor signals to and from the brain. The cord is suspended within cerebrospinal fluid and enclosed in membranous tissue known as the meninges.

Spinal canal – This is the long opening down the middle of the spine, through which the spinal cord extends vertically.

Vertebral foramen – A foramen is an opening within the body, and the vertebral foramina are formed by openings within the vertebral arches. The spinal canal is formed by the stacking of these openings.

Intervertebral foramen – In addition to the spinal canal, the vertebrae are constructed in such a way that the nerve roots are provided openings to exit the spinal column. These lateral (right and left side) openings are known as intervertebral foramina.

Ligamentum flavum – In addition to muscle tissue, the vertebrae are connected by ligaments. Each vertebral segment is supported by its own section of ligament, and these collectively are known as the ligamenta flava.

This brings us back to the intervertebral discs, of which there are 23 or 24 within the typical human spine. They are located between the vertebrae, where they help connect the bony segments while simultaneously providing cushioning and enabling flexibility. The discs are anchored above (superiorly) and below (inferiorly) to the vertebrae by vertebral endplates, which are thin layers of thickened bone. The discs, which are shaped roughly like flattened kidney beans, are composed of two main parts:

Annulus fibrosus – This is the layered, cartilaginous outer wall of the disc. It is made up of 15 to 25 concentric layers of collagen. These layers are called lamellae. The outer wall of the disc is only slightly innervated, compared to other portions of the spine. However, there are nerve endings within the lamellae that are capable of sending pain signals to the brain when irritated.

Nucleus pulposus – This is the gelatinous center portion of the disc. It is high in water content and serves two main functions: to bear the brunt of the downward force on the spine, and to act as a “pivot point” for spinal movement. The nucleus exerts constant pressure on the disc’s outer wall.

As mentioned earlier, a disc extrusion occurs when a portion of the nucleus pulposus leaks through a tear or rupture in the annulus fibrosus. An extrusion of nucleus material actually is the second phase of a potentially three-phase process of disc degeneration. It begins with a disc protrusion, or bulging disc, in which pressure on the outer wall of a disc forces it out of its normal boundary. Should fissures form all the way through the outer wall, nucleus material can extrude into the spinal canal. If that extruded nucleus material breaks away from the disc and floats as free fragments in the spinal canal, it is known as sequestration.

The area of the spine most likely to develop a disc problem is the lower back, or lumbar spine. That is due to the fact that the anatomical components of that region bear most of the body’s weight, as well as the stress-inducing motion that takes place in the lower back. The neck (cervical) region is the second-most common location for disc-related problems, for similar reasons; the weight of the head is supported by the neck, which is also extremely flexible.

Regardless of their location within the spine, disc protrusion, extrusion, and sequestration might produce localized pain when the tiny nerve endings located within the disc’s outer wall are irritated. This is known as discogenic pain, and it typically does not become debilitating. However, if a portion of a disc’s outer wall or extruded nucleus material makes contact with the spinal cord or an adjacent nerve root, it can produce radiculopathic symptoms such as radiating pain, tingling, numbness, or muscle weakness. These symptoms are discussed in detail below, immediately following a discussion of the causes and risk factors of a disc extrusion.

Causes and Risk Factors of a Disc Extrusion

The intervertebral discs are exposed to a great deal of wear and tear over the years. They are stretched and compressed with nearly every movement the body makes. Their elasticity allows them to “snap” back into shape after each movement, but this elastic quality begins to fade over time. The nucleus gradually loses water content, while the outer wall begins to become brittle and less flexible. It is a natural part of aging, and everyone experiences it eventually. However, not everyone experiences a disc extrusion, or the precursor, a bulging disc.

Why do some people develop these conditions, and others do not? There are a number of factors at work, including:

Genetics – As with most degenerative spine conditions, there is a genetic component to the development of a disc extrusion. If a close relative, particularly a parent or grandparent, suffered from a herniated disc, you are more likely to develop that condition. This is not universally true, of course, but a doctor will likely ask about family medical history when attempting to diagnose back or neck pain.

Work and pastimes – Someone whose profession or hobbies require a great deal of repetitive motion or extended periods of sitting (such as a truck driver or office worker) is more likely to place greater stress on the discs. This, in turn, exacerbates the degenerative process. An example of this is neck or back pain that develops over time in golfers, who must utilize the spine in a repetitive, demanding capacity while swinging the club. No matter what job or athletic pastimes someone participates in, it is vitally important to practice proper posture in order to alleviate any excess pressure on the discs and other anatomical components of the spine.

Eating habits and body weight – People who are overweight naturally place more stress on the spinal anatomy. The discs bear the downward, or axial, load placed upon the spine by the weight of the body, exerting pressure within the nucleus and upon the outer wall. It only makes sense that the more weight the discs must bear, the faster they will degenerate. To combat that, it is vital to follow a healthy diet and exercise regimen.

In addition, people who smoke might be more susceptible to accelerated disc degeneration. The ingredients in cigarettes and other tobacco products inhibit circulation and slow the delivery of reparative nutrients to the spinal anatomy and other parts of the body.

Another potential factor in the development of a disc extrusion is traumatic spine injury. Of course, someone who is involved in an accident, as with a car crash, might experience acute damage to one or more discs. Far more common are the long-reaching after-effects of a spine injury suffered during childhood or adolescence. People who spend their formative years participating in contact sports, such as football or field hockey, might suffer back or neck injuries that seem to heal with no adverse effects in the short term. However, a long-ago injury may have altered the shape of the spine through the development of scar tissue, or through a slight displacement of one or more vertebrae. By the time someone who has suffered such an injury reaches his or her 30s, the slightly altered spinal architecture has begun to deteriorate at a greater rate than a healthy spine. This type of premature deterioration is an extremely common cause of disc-related problems for adults in their mid-to-late 30s.

At AOMSI diagnostics, we provide the most accurate spinal imaging available in the healthcare marketplace. This imaging has been proven in peer-reviewed medical journals to be the most accurate, reliable, and specific spinal imaging when compared to traditional spinal imaging modalities. Often times we are able to expedite pre-authorizations for surgery or even overturn denials for spinal surgery after the VMA study is presented to insurance.