Degenerative Disc Disease
Degenerative Disc Disease (DDD) is a broad term applied to a gradual condition that can develop throughout the entire spine. Although DDD is relatively common, its effects are usually not severe enough to warrant medical attention. In clinical practice, the lumbar and cervical spine is more frequently affected than the thoracic area.
How Does the Disc Degenerate?
The intervertebral disc is a structure located between two vertebras. It may function is to provide a “shock absorber” effect to the spine. It also allows increase movement in the spine. Factors associated with DDD are related to aging, trauma, lifestyle related conditions (obesity and smoking) and genetics. Degenerative changes are associated with wear and tear, ultimately creating loss of normal structure and function.
Long before Degenerative Disc Disease can be seen radiographically, biochemical and histologic (structural) changes occur. Some of these changes are not unlike those associated with osteoarthritis.
Over time, certain changes in the cellular structure of the annulus fibrosus (outer fibrous wall) of the disc, cause weakens and may become structurally unsound. Additionally, the ability of the nucleus (inside gel of the disc) to retain water is decreased. These changes may lead to the disc’s inability to handle mechanical stress. The underlying changes can result in conditions such as disc herniations, potentially creating nerve pressure (sciatica), spine narrowing (spinal stenosis) and disc space collapse creating back pain from multiple sources such as the facet joints.
Although 80% of the adults will ultimately experience symptoms from DDD, only 1-2% will eventually undergo a surgical procedure.
During the acute phase, bed rest may be recommended for a few days, but beyond that experts advocate stretching, flexion and extension exercises, and no/low impact aerobics. Of course, each patient is different and therefore so is their treatment plan.
It is of outmost importance to obtain a precise diagnosis of which structure in the neck and back is responsible for the specific pain, in order to provide adequate treatment.
In some patients, the pain response may limit their flexibility. Prescribed stretching exercises can improve flexibility of the trunk muscles. Flexion exercises may help to widen the intervertebral foramen. The intervertebral (between the vertebrae) foramen are small canals through which the nerve roots exit the spinal cord. The intervertebral foramen are located on the left and right sides of the spinal column.
Extension exercises, such as the McKenzie method, focuses on the muscles and ligaments. These exercises help maintain the spine’s natural lordotic curve, important to good.
Aerobics (no/low impact) offers many benefits including improved muscular endurance, coordination, strength, strong abdominal muscles, and weight loss. Strong abdominal muscles work like a brace (or corset) to reduce the loads to the lumbar spine. It is also known that aerobics help to combat anxiety and depression. The loads on the discs during walking are only slightly greater than when lying down. Walking, bicycling, and swimming are forms of aerobic exercise a physician may suggest.
Acupuncture, a type of alternative medicine, has been shown to control pain. It has been suggested that acupuncture stimulates the production of endorphins, acetylcholine, and serotonin. However, acupuncture should be combined with an exercise program for many of the reasons outlined in prior paragraphs. Other techniques such as TENS, muscle stimulation, Myofascial release and other have been use with various degree of success.
During the acute phase of low back or neck pain , drugs may be prescribed. Some of these may include narcotics, acetaminophen, anti-inflammatory agents, muscle relaxants, and anti-depressants. Narcotics are used on a short-term basis partially due to their addiction potential. When low back pain is caused by muscle spasm, a muscle relaxant may be prescribed. These drugs have sedative effects. Depression can be a factor in chronic low back pain. Anti-depressant drugs have analgesic properties and may improve sleep.
Today manipulation is performed by Chiropractors and Physical Therapists. For patients without radiculopathy (pain stemming from a spinal nerve root), manipulation may be effective during the first month. Thereafter, benefits are unproven. Manipulation is believed to be effective because of its effect on spinal mobility. Acute low back pain, chronic low back pain, and DDD without nerve compression may respond to manipulation.
Usually during the first six weeks, acute low back pain is treated with a couple of days of bed rest (slightly longer with herniated disc) and appropriate medication. Muscle relaxants are seldom used for longer than one week. Early ambulation is encouraged to increase circulation (aids healing), improve flexibility, and build strength.
Generally, during the first two to three weeks the acute symptoms subside. Aerobic (no/low impact) exercise may be started three times per week along with daily back exercises. Some patients may be referred to physical therapy or a supervised work-conditioning program.
If the symptoms of DDD and low back or neck pain persist despite non-operative treatment, further diagnostic tests may be necessary. These tests may include an MRI, CT Scan, Myelogram, or diagnostic and therapeutic injections such as epidural steroid injections, facet injections, trigger point injections and discography.
Although most DDD patients with herniations respond well to non-operative treatments, a small percentage do not. Disc herniation is the most common indication for spinal surgery. In fact, 75% of all spinal surgeries are for a herniated disc.
Interventional Pain Management
Frequently, in spite of aggressive conservative treatment, the pain persists creating functional disability. During this period a referral to a pain management specialist trained in spinal therapeutic and diagnostics is indicated. There are multiple interventions that can be offered depending on the specific source of the pain. For more information see: epidural steroid injection, facet injections, trigger point injections and discography.
Lumbar herniation causing loss of bowel or bladder control, or major lower extremity deficit, requires immediate surgery. These symptoms (Red Flags) are caused by nerve root compression. Cauda Equina Syndrome is a serious disorder that may be caused by a large central herniation. The cauda equina begins at the end of the spinal cord. The cauda sac is filled with nerves resembling the tail of a horse. When this sac is compressed the patient may present with the following symptoms: low back pain, bilateral lower extremity weakness, radiculopathy (pain from a nerve root), and incontinence.
When these symptoms present, surgery is required immediately. Most herniated discs often do not require surgical intervention and respond quite nicely to non-surgical treatments (within 6 weeks).
The type of surgical procedure(s) is dependent on the patient, the diagnosis, and the goals of surgery. Frequently a diagnostic test such a discography is indicated in assessing which disc is the pain generator. It also yields useful information in planning a surgical intervention.
Recent advances in minimally invasive interventions such as IDET (intradiscal electrothermal therapy) show promising results in patients with painful disc and mild to moderate loss of disc heights.
Surgical removal of an inferior disc may involve a limited laminotomy and partial disc excision. The disc fragments are removed and the nerve is decompressed. Micro-discectomy is often a preferred procedure requiring smaller incisions resulting in reduced scarring and a more rapid recovery.
If the entire disc is removed, spinal column instability may warrant fusion. Patients who are obese, smoke, or who have psychological problems exhibit lower rates of success. Smoking in particular negatively impacts the process of fusion and healing in general. Spinal fusion may be combined with spinal instrumentation, the use of medically designed hardware (e.g. screws, cages).
Very frequently, the most neglected aspect and usually the most important adjuvant treatment is related to lifestyle changes. Specific interventions such as weight reduction, smoke cessation, exercise, treatment of alcohol or chemical dependency, remain the mainstay in preventing and maintaining gains made through the above mention interventions.