Back pain is one of the most common health problems facing people today. It is the second most common reason for a doctor’s visit, behind only to the common cold. Billions of dollars are spent annually on treating back pain, which is also a very common cause of disability. More than 90% of people will experience an episode of debilitating back pain at some point in their lifetime.
While there are many causes of back pain, the most common cause is a disorder of the lumbar intervertebral discs. The spine is divided into three parts, and the lumbar spine is the lowest part of the spine. The intervertebral discs are shock absorbers, or spacers, that are located in the spine between the bones of the spine, called vertebrae (hence the name “intervertebral”). The makeup of a disc is similar to that of a jelly donut, in that it has a soft gel-like center called the nucleus pulposus, which has a very limited blood supply, and a thicker outer fibrous structure called the anulus fibrosis, which has sensitive nerves dispersed within it. The purpose of the disc is to allow movement and to provide shock absorbing capability. However, much like a jelly donut, if too much pressure is applied, the disc can bulge out of place or break apart. This is called a “herniation.”
This gel is composed of many inflammatory mediators, and as a result, is very irritating to the surrounding structures. When the disc is disrupted, it is frequently associated with back pain, whether the cause is trauma, genetic predisposition, or poor strength of the “core” muscles that provide some support to the spinal structures. This back pain is thought to be due in part to the inflammatory mediators that are released, and due to the disruption of the anulus fibrosis, among other things. If spinal nerves are compressed or irritated, this can lead to another problem, called “radiculopathy,” meaning pain from an irritated or pinched spinal nerve, and also known commonly as “sciatica.” Information on radiculopathy can be found here.
The back pain associated with intervertebral disc disruption is called “discogenic” pain. The more common phrase used to describe disc-related pain is pain of “degenerative disc disease.” Although frank herniations can certainly be a cause of back pain, more subtle disc problems, such as a simple tear of the anulus fibrosis or subtle derangements of the more central part of the nucleus pulposus, can be associated with back pain. Further complicating matters, it has also been shown that completely normal looking discs on a magnetic resonance image (MRI), which is the best test to look at the intervertebral discs, can be associated with back pain. When the outer part of the disc appears normal, and the disc is proven as painful due to internal derangement, this is called internal disc disruption syndrome. Again, the back pain caused from all of these issues above is called discogenic pain, and some of these terms are more broadly classified as degenerative disc disease.
As the life of a disc progresses, it naturally loses hydration, gradually. This is universal, and will happen to us all. Fortunately, similar to how a normal appearing disc can cause discogenic pain, the converse is far more prevalent. Most degenerative discs do not cause debilitating back pain, and in fact the vast majority may be completely painless. Dehydrating discs are like graying hair, or wrinkling skin. If we’re lucky to live long enough, we are going to have degenerative discs on an MRI, or what a radiologist may call “degenerative disc disease”, frequently abbreviated as “DDD”. The term “Degenerative disc disease” may be used to describe a disc with a tear in it, a bulging outwards, a loss of height, or darker color on specific MRI sequences.
Do not panic if you’ve been told you have this. You are not alone. This is not a “disease” in the traditional sense of the world. This is not a life and death situation, and you cannot die from degenerative disc disease. This can, however, be a quality of life issue. While degenerative discs are not always associated with pain, they can be.
The type of pain that people describe most frequently is a dull ache with pressure across the low back, occasionally referred down to the tailbone area and up the back a little bit, and often across to both sides and even into the top part of the buttocks. Sometimes a dull aching feeling can even extend into the thighs. If there is leg pain coming from the discs, the leg pain should not be as intense as the back pain, and is unlikely to extend below the knees. One particularly stoic patient of mine described his back pain as a feeling of the back simply being “tired”. Although less common, disc pain can be sharp, stabbing, lancinating, burning, and even more uncommonly associated with tingling and numbness.
Aggravating factors are things that put pressure on the discs and increase the stress on the lumbar spine. People often describe staying in any one position too long as a common factor. Although standing on hard surfaces, such as in line at an amusement park, can cause discogenic pain, sitting is one of the most common exacerbating factors. The longer one sits in one position, the more prevalent their discogenic pain may become. Individuals often describe a need to keep moving or shifting in their seat, or getting up and standing in the back of a movie theater or classroom.
Long airline flights stuck in a window seat, or sitting in courtroom or in church are common aggravators. Bending, twisting, coughing, sneezing and jumping-related impact activities, such as basketball, or even teaching a child how to do jumping jacks, can all cause discogenic symptoms also. Other common aggravating factors include standing and slightly bending forwards at the waist. Shoveling snow, digging a hole for a fencepost, changing sheets on a bed, packing a suitcase for a trip, washing a car and even things seemingly far less strenuous, such as standing and doing dishes, washing hands, and even brushing teeth can be agonizing for people with discogenic pain.
The good news is that discogenic pain flare-ups nearly always subside spontaneously, within a certain period of time. How long it takes is variable. Often the individual will describe intermittent pain for a few days at a time, occurring once every few years. With the progression of time, the flare ups may become more intense and more frequent, with a longer duration before subsiding. The pain can eventually become constant. Patients frequently describe experiencing stiffness and pain when getting out of bed in the morning, with loosening up and improvement of symptoms over the course of 30-90 minutes. Increasing discomfort usually occurs at the end of the day in these cases. The pain can sometimes interfere with a good night’s sleep as well.
The bad news is that while many treatment options exist, there is no long-term, permanent cure for discogenic pain, and degenerative disc disease is not reversible… again, like wrinkling skin and graying hair. Many treatment options exist, and many factors play into how much someone’s life will be affected. Initial strategies, in addition to minimizing exacerbating factors, include over-the-counter medications such as acetaminophen, and ibuprofen or naproxen, along with strategies such as smoking cessation, weight reduction and core strengthening with the guidance of a physical therapist. Recent research has shown that a technique called “cognitive behavioral therapy” in addition to physical therapy and subsequent home exercises have been show to be as effective at long term management of chronic back pain as major back surgery.
Various injection strategies have been used to treat discogenic pain, and while injection strategies have been show in some cases to decrease pain substantially, a long term benefit should generally not be expected unless other strategies are employed as well, such as those mentioned above. The most common injection strategy used to treat discogenic pain is the x-ray guided epidural steroid injection. These procedures are done over a million times a year in the United States alone. Side effects do exist, and these procedures should only be done by an experienced medical doctor well-trained in carefully performing such procedures.
Major back surgery is mentioned briefly as a treatment option above. The most common surgery for back pain is called a “fusion”. Historically, fusions have been done to treat joint related pain when the joint cannot be salvaged, and the expected pain relief and benefit with subsequent improvement in quality of life outweighs the consequences of the joint fusion. Fusion means that the affected joint is obliterated, and the two bones that make up the joint are “fused” together into one solid bone. This is frequently done using bone from a cadaver or other type of donor, and many times with “hardware” meaning rods and screws. In the spine, this means completely removing the presumably painful intervertebral disc, and turning the vertebrae above and below the disk into one solid piece of bone. While in many cases fusions have provided substantial benefit, many risks exist, and overall, the long-term outcomes of spinal fusions are conflicting and many do not show clear benefit. As with injections, and all other options above, while benefit can be obtained from a fusion, a good outcome cannot be guaranteed and by no means should it ever be looked at as a “cure”.
Where does all of this information lead us? We are lead to degenerative disc disease being a universal issue, affecting nearly every one of us one of us if we live long enough. We may or may not have pain from it, and no cure exists. Coping strategies and a generally “healthy” lifestyle, minimizing exacerbating factors are critical. More research is needed, and it is being done. Most of all, if you are told you have “degenerative disc disease” don’t panic. Remember that there are other causes of back pain as well, and frequently pain has many sources. A part of your pain may be discogenic, but the pain could be coming from other areas of the spine as well. See a well-trained medical doctor who can accurately assess whether or not your pain is related to this entity or something else, and guide you to what treatment options exist for you.
Your doctor will begin by taking a history and performing a physical examination, and may order X-ray studies of your back. However, sometimes it is difficult to see a crack and/or slippage on an X-ray image, so additional tests may be needed. A computed tomography (CT) scan can show a crack or defect in the bone more clearly. A magnetic resonance imaging (MRI) scan may be ordered to clearly show the soft tissue structures of the spine (including the nerves and discs between the vertebrae) and their relationship to the cracked vertebra and any slippage. It also will show whether any of the nearby discs have suffered any wear and tear because of the spondylolisthesis (slippage).
If isthmic spondylolisthesis is present, it can be graded as I, II, III or IV (Figure 2) based on how far forward the vertebra has slipped.
Cognitive Behavioral Therapy
Epidural Steroid Injections