Degenerative disc disease

Overview

Degenerative disc disease (DDD) affects the discs that separate the spine bones. As you age, the spine begins to show signs of wear and tear as the discs dry out and shrink. These age-related changes can lead to arthritis, disc herniation, or spinal stenosis. Pressure on the spinal cord and nerves may cause pain. Physical therapy, self-care, medication, and spinal injections are used to manage symptoms. Surgery may be an option if the pain is chronic.

Anatomy of the discs

Your spine is made up of a column of bones called vertebrae. Between each vertebra is a shock-absorbing disc that prevents the bones from rubbing together. Discs are designed like a radial car tire. The tough outer wall, called the annulus, has crisscrossing fibrous bands, much like a tire tread. These bands attach to each vertebra bone. Inside the disc is a gel-filled center called the nucleus, much like a tire tube (Fig. 1). Learn more at Anatomy of the Spine.

What is degenerative disc disease?

Degenerative disc disease (spondylosis) can occur in any area of the spine. It’s a condition in which your discs lose their flexibility and height to cushion the spine. Discs have a limited blood supply, so once injured they can’t repair themselves easily. Age-related changes to discs include (Fig. 2):

• Discs dry out and shrink: the disc nucleus is made of about 80% water. As you get older it slowly loses water and flexibility, which puts more stress on the disc annulus.
• Small tears in annulus: the gel-like nucleus can push through cracks in the disc wall. The nucleus has inflammatory proteins that can irritate nerves and cause pain. Tiny nerves in the annulus cause discogenic pain with small micro-motions of the disc. Over time the proteins dry up, and the discs become stiffer.
• Disc gets thinner: due to the loss of water, the discs get thin and the distance between vertebrae begin to collapse. Which is why we get shorter as we age.
• Bone spurs grow: without the discs holding apart the vertebrae, they can rub on each other causing abnormal bone growths.
• Excess motion: abnormal rubbing adds stress to the facet joints. Pinched nerves may result in neck, arm, back, or leg pain (sciatica).
• Spinal canal narrows: stressed ligaments and facet joints enlarge as they try to compensate and spread the load over a larger area. This over-growth causes the spinal canal to narrow, which can compress the spinal cord and nerves resulting in pain (see Spinal Stenosis).

What are the symptoms?

The symptoms of a degenerative disc vary from person to person. Some people have no pain, while others may experience intense pain that interferes with daily activities.

People commonly report underlying pain that is a nagging annoyance, with occasional flare-ups of intense muscle pain. These episodes last from a few days to a few months.

Pain and stiffness can occur in the neck or low back. You may also feel numbness or tingling “pins and needles.”

A cervical degenerative disc may cause a stiff neck along with pain in the neck and shoulders. Pinched nerve pain may radiate into the arms and hands. Headaches at the back of your head can occur.

A lumbar degenerative disc may cause low back pain and stiffness. Pain may spread to the buttocks or down one or both of your legs (sciatica). Weakness in your leg or foot can cause balance and gait problems. If your toes drag the floor when you walk (foot drop), consult your doctor right away.

Activities such as sitting, bending, or twisting may make your pain worse, while lying down tends to relieve the pain. You may feel better if you walk or run rather than sit or stand for too long.

Symptoms of disc disease tend to be more severe between ages 30 to 50. But later in life, your discs will have dried out and stabilized causing less pain.

What are the causes?

In addition to age and injury, arthritis and osteoporosis contribute to disc degeneration. Lifestyle habits such as obesity, smoking, poor posture, and weak muscles strain the discs.

It’s not known why some people have pain and others don't. Various factors contribute to disc degeneration including: genetic, autoimmune, inflammatory, and traumatic.

Who is affected?

This condition can affect young adults who lead active lifestyles. Most of the time it occurs slowly and does not cause symptoms until middle age. People who smoke are at greater risk for disc disease, as are people who work in certain jobs.

How is a diagnosis made?

When you first experience pain, consult your family doctor. Your doctor will take a complete medical history to understand your symptoms, prior injuries, and if lifestyle habits are causing the pain. Next a physical exam is performed to determine the source of the pain and test for any muscle weakness or numbness.

Your doctor may order imaging studies: X-ray, MRI scan, discogram, myelogram, or CT scan to identify disc problems or other conditions. Based on the results, you may be referred to a neurologist, orthopedist, or neurosurgeon for treatment.

What treatments are available?

While disc degeneration can’t be reversed, there is evidence that exercise, lifestyle changes, and pain management can give you a better quality of life. Nonsurgical treatment is the first step.

If conservative therapies fail to help you manage and control the painful symptoms, your doctor may recommend surgery.

Nonsurgical treatments

Self care. Using correct posture (see Posture & Body Mechanics) and keeping your spine in alignment are the most important things you can do for your back. You may need to make adjustments to your daily standing, sitting, and sleeping habits. You may also need to learn proper ways to lift and bend (see Self Care for Neck and Back Pain). Your workspace may need to be rearranged to keep your spine from being under stress.

Stress is a big obstacle to pain control. Pain increases when you are tense and stressed. Relaxation exercises are one way of reclaiming control of your body. Deep breathing and other techniques can help you to better manage the pain you live with (see Pain Management).

Physical therapy. The goal of physical therapy is to help you return to full activity. Physical therapists can instruct you on proper lifting and walking techniques. They’ll work with you to strengthen and stretch your muscles (see Coping with Back Pain). They’ll also encourage you to increase the flexibility of your spine, arms and legs. Activity modification, rest, and application of ice may be helpful in the acute stages. Exercise and strengthening are key elements to your treatment and should become part of your life-long fitness.

Chiropractic. A spinal adjustment applies pressure to an area that is immobile and realignes the joints to more normal motion. Good motion helps reduce pain and muscle spasms. Motion also reduces the formation of scar tissue, which can lead to stiffness (see Chiropractic Care).

Medications. Your doctor may prescribe pain relievers, nonsteroidal anti-inflammatory medications (NSAIDs), steroids, or muscle relaxers.

• Nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin, naproxen (Naprosyn, Aleve), ibuprofen (Motrin, Nuprin, Advil), and celecoxib (Celebrex) are used to reduce inflammation and relieve pain.
• Analgesics, such as acetaminophen (Tylenol) can relieve pain but don’t have the anti-inflammatory effects of NSAIDs. Long-term use may cause stomach ulcers as well as kidney and liver problems.
• Steroids can be used to reduce the swelling and inflammation of the nerves. The pills are taken orally (as a Medrol dose pack) in a tapering dosage over a five-day period.

Steroid injections. The procedure is done under x-ray guidance and involves an injection of corticosteroid and a numbing agent into the spine. The medicine is delivered next to the painful area to reduce the swelling and inflammation of the nerves (Fig. 3). Repeat injections may be given to achieve full effect. Duration of pain relief varies, lasting for weeks or years. Injections are done in conjunction with a physical therapy and/or home exercise program. See epidural steroid injections and facet injections.

Holistic therapy. Some patients find acupuncture, acupressure, yoga, nutrition / diet changes, meditation, and biofeedback to be helpful in managing pain as well as improving overall health.

Surgical treatments
Surgery may be recommended if your symptoms have not improved with nonsurgical therapy.

At each level of the spine, there is a disc space in the front and paired facet joints in the back. Working together, these structures define a motion segment and permit range of motion. The goal of surgery is to stop the painful movement of the motion segment, restore the height of the disc space, and decompress the spinal nerves. You should understand what surgery can and can’t do, and whether it can relieve your symptoms. Talk to your doctor about whether surgery is right for you.

Spinal fusion surgery joins one or more of the bony vertebrae together to stabilize and stop painful motion. A spacer cage packed with bone graft is inserted into the collapsed disc space (Fig. 4). Over the next 3 to 6 months, the bone graft will fuse the vertebrae above and below into one solid piece of bone. Metal rods and screws may be used to immobilize the area while fusion is created.

One of the long-term risks of fusion can be degeneration of adjacent discs. The discs above or below the fusion take on more stress and load. The added wear and tear can lead to more rapid degeneration of those discs than might have occurred without the fusion.

Motion preservation surgery involves devices that stabilize the spine without fusing the bones together. The idea is to decrease the risk of adjacent segment disease caused by fusion, but as yet is unproven. Because these are relatively new techniques, there are no studies of long-term outcomes. Insurance companies classify many of these devices investigational and patients may have to pay for them out-of-pocket.

• Artificial disc replacement involves removal of the damaged disc and insertion of a moveable device that mimics a disc’s natural motion. Made of metal and plastic, they are similar to hip and knee joint implants.
• Dynamic stabilization involves the insertion of a flexible rod along the facet joints at the back of the spine. Pedicle screws are inserted into the bones above and below the damaged disc. A flexible connector permits a controlled range of bending, straightening and twisting movement.

Clinical trials

Clinical trials are research studies in which new treatments—drugs, diagnostics, procedures, and other therapies—are tested in people to see if they are safe and effective. Research is always being conducted to improve the standard of medical care. Information about current clinical trials, including eligibility, protocol, and locations, are found on the Web. Studies can be sponsored by the National Institutes of Health (see clinicaltrials.gov) as well as private industry and pharmaceutical companies (see www.centerwatch.com).

Sources & links

If you have more questions, please contact Mayfield Brain & Spine at 800-325-7787 or 513-221-1100.

 

Links

Spine-Health.com

SpineUniverse.com

Glossary

annulus (annulus fibrosis): tough fibrous outer wall of an intervertebral disc.

arthritis: joint inflammation caused by infection, immune deficiency (rheumatoid arthritis), or degeneration of the cartilage that causes pain, swelling, redness, warmth, and restricted movement.

degeneration: the gradual deterioration of specific tissues, cells, or organs resulting in a loss of function, caused by injury, disease, or aging.

disc (intervertebral disc): a fibrous cushion that separates spinal vertebrae. Has two parts, a soft gel-like center called the nucleus and a tough fibrous outer wall called the annulus.

discogenic pain: pain arising from degenerative changes in the intervertebral discs.

nucleus (nucleus pulposus): soft gel-like center of an intervertebral disc.

osteoporosis: a depletion of calcium in the bones making them weak, brittle, and prone to fracture. Common in elderly women after menopause. Can be prevented early in life with calcium and regular exercise to stimulate bone metabolism.

osteophyte: (bone spur) a bone projection that occurs near cartilage degeneration in joints. Often related to osteoarthritis.

radiculopathy: refers to any disease affecting the spinal nerve roots. Also used to describe pain along the sciatic nerve that radiates down the leg.

spondylosis: a spinal condition resulting from degeneration of the intervertebral discs in the spine causing narrowing of the space occupied by the disc and the presence of bone spurs.

spinal stenosis: the narrowing of the spinal canal and nerve-root canal along with the enlargement of the facet joints.

vertebra: (plural vertebrae): one of 33 bones that form the spinal column, they are divided into 7 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 4 coccygeal. Only the top 24 bones are moveable.

---

updated > 1.2023
reviewed by > Robert Bohinski, MD, PhD, Mayfield Clinic, Cincinnati, Ohio