Degenerative disc disease is often described as a "wear and tear" condition. For reasons not fully known, possibly mainly due to bad genes and partly due to ageing and other environmental factors , the water content of the disc between the back bones reduces over a period of time. This can be detected on MRI scanning and is generally regarded as being related to a wear process in combination with ageing. At some point, again for reasons which are poorly understood, this process may give rise to pain within the disc and therefore in the lower back. Pain related to a disk may radiate to the buttocks and into the back of the legs also.

Typically, pain related to a disc in the lower back is made worse by sitting rather than standing and may also be heightened by coughing, sneezing or straining. Any activity involving forward bending may also bring on or worsen the pain. Although the cause for the pain specifically is not well understood much research is currently in progress on this subject, and it seems that, at least in part, an inflammatory process involving irritative proteins in the region may perpetuate the problem.

Pain from a disc may give rise to protective spasm of the lower back muscles which may contribute to the symptoms. The process of wear is a slow one, initially obvious with heavy work or strenuous exercise and commonly only present from time to time. Symptoms of wear in the spine tend to wax and wane over a very long period, often arising for no particular reason being brought on and falling away again similarly. Very few people suffer constant pain on a daily basis without "good days and bad days".

Treatment, where possible, is often determined by the degree of pain and its constancy as well as the level of difficulty in undertaking normal daily activities and effect on quality of life. In the vast majority of cases, the onset of back pain from any specific event is likely to eventually subside although this may take many months.
The outer edge of the disc is a ring of gristle-like cartilage called the annulus. The centre of the disc is a gel-like substance called the nucleus. Discs have a high water content. As people age, the water content decreases, so the disc begins to shrink and the spaces between the vertebrae get narrower. Also, the disc itself becomes less flexible. Other conditions that can weaken the disc include:

The fibrous outer ring may crack or tear. Sometimes fragments of the disc enter the spinal canal where they can damage the nerves that control bowel and urinary functions.

Symptoms Pain in the involved areas of the spine and, in some instances, pain or numbness to the arms or legs. Loss of flexibility is also typical. Although the problem may reside in the disc between the vertebrae, pain is commonly referred to the region of the buttocks or, in some instances, down the back of the thighs. Referred pain from the disc itself rarely goes below the level of the knee in the absence of a pinched nerve.

Typically discal pain is more severe with coughing, sneezing or forward bending of the spine and in sitting, particularly for long distances such as in car or plane travel. Typically the pain increases over the course of the day and tends to be worse with heavy physical activity or sports.

Treatment Options For most people, degenerative disc disease can be successfully treated with conservative care. Most patients will experience low-grade continuous but tolerable pain that will occasionally flare (intensify). The frequency and intensity of the flares can be managed with an exercise program. The best manner in which to manage long term tolerable lower back pain is hotly debated. Exercises vary in their aims, however there is a reasonable body of evidence to suggest that overall aerobic fitness programs aimed at increasing general cardiovascular fitness are as effective as more specific exercise regimes for the muscles of the lower back and abdomen.

Although it may be unexpected, in the long term people with degenerative disc pain benefit most from increased physical activity and not rest. This seems hard to understand when, for example, an injury to the knee needs rest and gradual increase in activity.

In the lumbar spine the improvements in general fitness and weight control which stem from regular activity of any kind seem to be protective against relapses of chronic back pain. Even when back pain has flared up acutely, the best results are obtained from an early return to physical activity, including work. These and other principles are employed in back rehabilitation programs such as Gregory Terrace Rehabilitation.

Pain related to the facet joints is typically made worse by stress to these joints which are located on the posterior aspect of the spine. The pain may be increased by backwards arching of the spine such as hanging clothes out on a clothesline, for example, or walking down stairs or an incline. The pain is typically most severe when standing and least severe when sitting as the spine becomes more flexed in its position and stress is taken off the joints.

Similarly, when pain from prolonged standing or walking worsens patients tend to lean forward to relieve pressure on the facet joints. Sometimes this may lead to the use of a walking stick. Often the pain is situated slightly to the side of the middle of the spine and it may be possible to identify which joint in the spine seems most problematic through various x-ray tests.

Surgery is rarely effective for back pain related to arthritis of facet joints. Unlike hip replacement and knee replacement operations which have been very helpful in addressing arthritis of these joints, there is no generally accepted surgical option which is effective in treating facet joint osteoarthritis.

Also, facet joint osteoarthritis commonly occurs at multiple levels of the spine which would make surgery far more extensive and less effective. Treatment of this condition usually involves non operative measures such as anti-inflammatory medication, a regular exercise program, lumbar corsetry and supports and, in some cases, radiologically guided injections of small quantities of local anaesthetic and corticosteroids into the affected joint. These injections may serve two purposes - assisting with the diagnosis and helping the pain.

What is a disc?

The disc is a soft tissue, elastic structure called a spinal disc, or intervertebral disc. It lies between each vertebral body. There is a naming system used based on which level the disc is located for example L12 disc means that it is located between the first and second lumbar vertebra.


What is the structure of the disc?

The intervertebral discs are composed of an annulus fibrosus and a nucleus pulposus.

The annulus fibrosus is a strong radial tire–like structure made up of lamellae; concentric sheets of collagen fibers connected to the vertebral end plates. The sheets are orientated at various angles. The annulus fibrosus encloses the nucleus pulposus.

Although both the annulus fibrosus and nucleus pulposus are composed of water, collagen, and proteoglycans (PGs), the amount of fluid (water and PGs) is greatest in the nucleus pulposus.

PG molecules are important because they attract and retain water. The nucleus pulposus contains a hydrated gel–like matter that resists compression. A healthy disc in a young adult consists of approximately 90% water. The amount of water in the nucleus varies throughout the day depending on activity.


What is the function of the discs?

The intervertebral discs are fibrocartilaginous cushions serving as the spine's shock absorbing system, which protect the vertebrae, brain, and other structures (i.e. nerves). The discs allow some vertebral motion: extension and flexion. Individual disc movement is very limited – however considerable motion is possible when several discs combine forces.

Together, the disc forms a hydraulic "shock absorber", able to cushion the stress during movement of the spine. The intervertebral discs help the spine return to and keep its normal curves following any spinal movement.


Why is the disc prone to damage?

Discs are not vascular and therefore depend on the end plates to diffuse needed nutrients. The cartilaginous layers of the end plates anchor the discs in place. As one ages these pores get blocked off and no nutrition goes to the disc. This is the reason they do not heal when a tear occurs.


What is the cause of disc damage?

There is an interplay between genetic and environmental factors.


What Is Degenerative Disc Disease (DDD)?

Degenerative disc disease (DDD) is part of the natural process of growing older. As we age, our intervertebral discs lose their flexibility, elasticity, and shock absorbing characteristics. The outer fibers that surround the disc, called the annulus fibrosis, become brittle and are more easily torn. At the same time, the soft gel-like center of the disc, called the nucleus pulposus, starts to dry out and shrink. The combination of damage to the intervertebral discs, the development of bone spurs and the gradual thickening of the ligaments that support the spine can all contribute to degenerative arthritis of the lumbar spine.

To a certain degree, this process happens to everyone. However, not everyone who has degenerative changes in their lumbar spine has pain. Many people who have "normal" backs have MRIs that show disc herniations, degenerative changes, and narrowed spinal canals. Every patient is different, and it is important to realize that not everyone develops symptoms as a result of degenerative disc disease.

What Are The Symptoms Of Degenerative Disc Disease?

When degenerative disc disease becomes painful or symptomatic, it can cause several different symptoms due to the compression of the nerve roots. Depending on where your degenerative disc is located, it could cause

  • Back pain
  • Radiating leg pain
  • Neck pain
  • Radiating arm pain

These symptoms are caused by the fact that worn out discs are a source of pain because they do not function as well as they once did, and as they shrink, the space available for the nerve roots also shrinks. As the discs between the intervertebral bodies start to wear out, the entire lumbar spine becomes less flexible. The result can be back pain and stiffness, especially towards the end of the day.


How Is Degenerative Disc Disease Diagnosed?

The diagnosis of degenerative disc disease begins with a complete physical examination. Your doctor will examine your back for flexibility, range of motion, and the presence of certain signs that suggest your nerve roots are being affected by degenerative changes in your back. This often involves testing the strength of your muscles and your reflexes to make sure that they are still working normally. You will often be asked to fill out a diagram that asks you where your symptoms of pain, numbness, tingling and weakness are occurring.

A series of x-rays is also usually ordered for a patient with back pain. If degenerative disc disease is present, the x-rays will often show a narrowing of the spaces between the vertebral bodies, which indicates the disc has become very thin or has collapsed. Bone spurs also can form around the edges of the vertebral bodies and also around the edges of the facet joints in the spine. These bone spurs can be seen on an x-ray, and are also called osteophytes. As the disc collapses and bone spurs form, the space available for the nerve roots starts to shrink. The nerve roots exit the spinal canal through a bony tunnel called the neural foramen, and it is at this point that the nerve roots are especially vulnerable to compression.


In many situations, doctors will order a MRI or a CT scan (CAT scan) to evaluate the degenerative changes in the lumbar spine more completely. A MRI is very useful for determining where disc herniations have occurred and where the nerve roots are being compressed. A CT scan is often used to evaluate the bony anatomy in the spine, which can show how much space is available for the nerve roots and within the neural foramina and spinal canal.


How Is Degenerative Disc Disease Treated?

Your doctor will discuss with you the treatment options appropriate for your diagnosis.

For most people who do not have evidence of nerve root compression with muscle weakness, conservative, non-surgical therapies, such as medication, rest, exercise and physical therapy, are typically recommended.

Surgery is offered only after conservative treatment has have failed to adequately relieve the symptoms of pain, numbness and weakness over a significant period of time.


What is a herniated disc?

A herniated disc, also called a bulging disc, ruptured disc or slipped disc, occurs when the inner core of the spinal disc pushes out through the outer layer of the disc.

Herniation describes an abnormality of the intervertebral disc that is also known as a "slipped," "ruptured" or "bulging" disc. This process occurs when the inner core (nucleus pulposus) of the intervertebral disc bulges out through the outer layer of ligaments that surround the disc (annulus fibrosis). This tear in the annulus fibrosis causes pain in the back at the point of herniation. If the protruding disc presses on a spinal nerve, the pain may spread to the area of the body that is served by that nerve.


What Are The Symptoms Of A Herniated Disc?

Usually, the main symptom is sharp, acute pain. In some cases, there may be a previous history of localized low back pain, with pain also extending down the leg served by the affected nerve. This pain is usually described as a deep, sharp pain, which gets worse as it moves down the affected leg. The onset of pain with a herniated disc may occur suddenly or it may be preceded by a tearing or snapping sensation in the spine, which may be attributed to a sudden rupture in the annulus fibrosis.


How Is A Herniated Disc Diagnosed?

A patient with a herniated disc will usually complain of low back pain that may or may not radiate into different parts of the body, such as the leg. They will often demonstrate a limitation in range of motion when asked to bend forward or lean backwards, and they may lean to one side as they try to bend forward. Patients will sometimes walk with a painful gait, flexing the affected leg so as not to put too much weight on the side of the body that hurts. Straight leg raising may be a positive indication of tension on the nerve root.

Abnormalities in the strength and sensation of particular parts of the body that are found with a neurological examination performed by a doctor provide the most objective evidence of nerve root compression. An MRI is the test of choice for diagnosis of a herniated disc, but a CT scan (CAT scan) also may be helpful because it provides better visualization of the bony anatomy of the spinal column that indicates where the source of pressure on the nerve root is located.


How Is A Herniated Disc Treated?

Treatment for the vast majority of patients with a herniated disc does not normally include surgery. Most patients will respond to conservative therapy, such as medication, rest and physical therapy. 


The primary element of conservative treatment is controlled physical activity. Usually treatment will begin with a modification of activity and then a gradual return to protected activities. Sitting, bending, lifting and twisting are not beneficial for this condition because they put a large amount of stress and pressure on the lumbar spine, which may increase the pressure on the affected nerve root. The appropriate use of medication is an important part of conservative treatment. This can include anti-inflammatory drugs, analgesics and muscle relaxants.An anti-inflammatory spinal injection for the area of the affected nerve root to lessen swelling and irritation caused by the damaged disc.


Surgery is typically recommended only after physical therapy, rest, and medications have failed to adequately relieve the symptoms of pain, numbness and weakness over a significant period of time.

The benefits of spine surgery, however, must be weighed against the risks. Your surgeon will be able to discuss the risks and benefits of surgery with you, and the likely results of operative versus non-operative treatment.