All about degenerative disc disease
There may be weakness, numbness, and pain that radiates down the leg.
Despite its name, degenerative disc disease is not a disease, but a natural occurrence that comes with aging.
The rubbery discs between the vertebrae normally allow for flexing and bending of the back, like shock absorbers. In time, they become worn, and they no longer offer as much protection as before.
The disc will sometimes bulge between the vertebrae. This is known as a herniated disc.
Treatment may include occupational therapy, physical therapy, or both, special exercises, medications, losing weight, and surgery.
Medical options include injecting the joints next to the damaged disc with steroids and a local anesthetic. These are called facet joint injections. They can provide effective pain relief.
Facet rhizotomy is a radiofrequency current that deadens the nerves around the facet joint, preventing pain signals from reaching the brain. Patients who respond well to facet joint injections may benefit from these. Pain relief may last for more than a year.
Intradiscal electrothermal annuloplasty (IDET) involves inserting a catheter into the disc and heating it. This appears to reduce pain, possibly by causing collagen to contract so that it repairs damage in the disc. The exact mechanism remains unclear.
Medications include pain relief medication, such as Tylenol, and non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen. Steroids and muscle relaxers may also be prescribed.
Some positions can help relieve symptoms. Kneeling or reclining, for example, may be less painful than sitting.
A corset or brace can offer support for the back.
Disc degeneration may cause no symptoms, or the pain may be so intense that the individual cannot continue with their daily activities.
The condition starts with damage to the spine, but in time, symptoms can affect other parts of the body. Symptoms usually get worse with age.
The discomfort can range from mild to severe and debilitating. It can lead to osteoarthritis, with pain and stiffness in the back.
The most common early symptom is usually pain and weakness in the back that radiates to another area.
If the damage is in the lower back, or lumbar spine, the discomfort may radiate to the buttocks and upper thighs. There may also be tingling, numbness, or both, in the legs or feet.
If the damage is in the neck area, or cervical spine, the pain may spread to the shoulder, arm, and hand.
There may also be instability in the spine, leading to muscle spasms in the lower back or neck, as the body tries to stabilize the vertebrae. This can be painful.
The individual may experience flareups of intense pain.
The pain may be worse when sitting, bending, lifting, or twisting. Walking, lying down, and changing position may help relieve it.
Intervertebral discs, also known as intervertebral fibrocartilage or spinal discs, provide the padding between the vertebrae of the spine. They have an elastic structure, made of fibrocartilage tissue.
The outer part of the disc is known as the annulus fibrosus. It is tough and fibrous, and it consists of several overlapping layers.
The inner core of the disc is the nucleus pulposus. It is soft and gelatinous.
The intervertebral discs cushion the stress when the spine moves or bears weight. They also help the spine to bend.
As people age, repeated daily stresses on the spine and occasional injuries, including minor, unnoticed ones, can damage the discs in the back.
- Loss of fluid: The intervertebral discs of a healthy young adult consist of up to 90 percent fluid. With age, the fluid content decreases, making the disc thinner. The distance between vertebrae becomes smaller, and it becomes less effective as a cushion, or shock-absorber.
- Disc structure: Very small tears or cracks develop in the outer layer of the disc. The soft and gelatinous material in the inner part may seep through the cracks or tears, resulting in a bulging or rupturing disc. The disc may break into fragments.
When the vertebrae have less padding between them, the spine becomes less stable.
To compensate, the body builds osteophytes, or bone spurs, small bony projections that develop along the edge of bones. These projections can press against the spinal cord or spinal nerve roots. They can undermine nerve function and cause pain.
Other problems include:
- a breakdown of cartilage, the tissue that cushions the joints
- a bulging disc, known as a herniated disc
- a narrowing of the spinal canal, or spinal stenosis
These changes can affect the nerves, leading to pain, weakness, and numbness.
Age is the biggest risk factor, but some other factors can speed up the process of degeneration.
- strenuous physical work
- tobacco smoking
- an acute or sudden injury, such as a fall
The doctor will ask about symptoms, when and where the pain occurs, whether there is tingling or numbness, and which situations cause the most pain. They will also ask about any falls, injuries, or accidents.
A physical examination may assess for:
- Muscle strength: The doctor may check for atrophy, wasting, or abnormal movements.
- Pain with motion or in response to touch: The patient will be asked to move in specific ways. If pressure applied to the lower back causes pain, there may be a degenerated disc.
- Nerve function: The physician taps different areas with a reflex hammer. Poor or no reaction could indicate a compressed nerve root. Hot and cold stimuli may be used to see how well the nerves react to temperature changes.
The doctor may order the following diagnostic tests:
- Imaging scans, such as CT or MRI, to gather information about the state of the spinal nerves, the discs, and how they are aligned.
- A discogram, which involves injecting a dye into the soft center of the disc, or several discs. The aim is to see whether the disc is painful. The dye shows up on a CT scan or X-ray. Discogram usage may be controversial, however, because herniated discs do not always cause symptoms.
The doctor may also test for other conditions, such as a tumor or other kinds of damage, to ensure a correct diagnosis.
Physical therapy and exercise that strengthens the core, such as yoga or pilates, can help manage degenerative disc disease.
Exercises can help to strengthen and stabilize the area around the affected disks, and to increase mobility.
Exercises that build the back and stomach muscles include walking, cycling, and swimming, as well as core strengthening programs, such as yoga and pilates.
The United Kingdom's National Health Service (NHS) recommends some simple exercises to try at home.
Lie on your back on the floor or on a bed, with the feet flat on the floor.
1. Press the lower back down into the floor. Hold for 5 seconds. Repeat 10 times.
2. In the same position, squeeze the buttocks together and gently lift them up to make a low bridge. If it is difficult to make a bridge, just squeezing the buttocks can help. Do this 10 times.
3. Gently move the knees from side to side.
Lifting weights may help, but this must be done under guidance and without bending the body.
Patients who do not respond to conservative therapies within about 3 months may consider surgery.
This may be an option if there is:
- back or leg pain that stops the patient from carrying out regular activities
- numbness or weakness in the legs
- difficulty standing or walking
The following surgical options are available:
If conservative management does not have the intended effect, spinal surgery may be required to correct the degenerated disc.
Stabilization surgery or spinal fusion: fusing two vertebrae together provides stability for the spine.
This can be done anywhere in the spine but is more common in the lower back and the neck area. These are the most movable parts of the spine.
This can relieve extreme pain in patients whose spine can no longer bear their weight, but it can also speed up the degeneration of the discs next to the fused vertebrae.
Decompression surgery: Various options to remove part of the joint of the disc can relieve the pressure on the nerves.
A patient who develops osteoarthritis, a herniated disc, or spinal stenosis may need other types of treatment.
Stem cell therapy
Researchers at the University of Queensland, Australia, have had some success with a tissue engineering-based approach using stem cells.
The aim is to encourage functional cartilage to generate itself, using an injectable hydrogel system. The researchers concluded that stem cell therapy might be useful for intervertebral disc regeneration.
The verdict is still out, and many more studies are needed to prove this treatment safe and effective.