Degenerative changes in the spine are often referred to those that cause the loss of normal structure and/or function. The intervertebral disc is one structure prone to the degenerative changes. These changes associated with and resultant from wear and tear, repetitive overuse and cumulative injuries, trauma, aging, even misuse (e.g. smoking). Repeated traumas such as motor vehicle accidents can accelerate degenerative changes and cause them to occur at an earlier age. These changes predominantly occur in the cervical(neck) and lumbar(lower back) spine.
Long before degenerative disc disease can be seen on an x-ray, biochemical and histologic (structural) changes occur. Some of these changes are similar to those associated with osteoarthritis.
Over time the collagen (protein) structure of the annulus fibrosus(outer part of disc) weakens and may become structurally unsound. Additionally, water and proteoglycan (PG) content decreases. PGs are molecules that attract water. These changes are linked and may lead to the disc's inability to handle mechanical stress. Understanding the lumbar spine carries a large portion of the body's weight; the stress from motion may result in a disc problem (e.g. herniation).
Despite its rather dramatic label, degenerative disc disease is fairly common, and it is estimated that at least 30% of people aged 30-50 years old will have some degree of disc space degeneration, although not all will have pain or ever receive a formal diagnosis. In fact, after a patient reaches 60, some level of disc degeneration is deemed to be a normal finding, not the exception.
Lumbar Degenerative Disc Disease- Pain and symptoms
Most patients with degenerative disc disease will experience low-grade continuous but tolerable pain that will occasionally flare (intensify) for a few days or more. Pain symptoms can vary, but generally are:
•· Centered on the lower neck or lower back, although it can radiate to the arms, hips and legs
•· Frequently worse when sitting, when the discs experience a heavier load than when patients are standing, walking or even laying down.
•· Exacerbated by certain movements, particularly bending, twisting or lifting.
The neck pain or low back pain associated with degenerative disc disease is usually generated from one or both of two sources:
•· Inflammation, as the proteins in the disc space irritate the surrounding nerves, and/or
•· Abnormal micro-motion instability, when the outer rings of the disc - the annulus fibrous - are worn down and cannot absorb stress on the spine effectively, resulting in abnormal movement of the joints and pain.
Excessive micro-motion, combined with the inflammatory proteins, can produce ongoing neck and low back pain.
How is Degenerative Disc Disease diagnosed
Following a review of the patient's history and a physical examination, a formal diagnosis of degenerative disc disease can be confirmed with magnetic resonance imaging (MRI). Plain film X-rays only depict decreased disc space but do not show the actual disc. MRI findings that are closely linked to a painful disc include disc space collapse of greater than 50% and cartilaginous endplate erosion. More controversial are MRI findings of early disc space degeneration such as disc desiccation (disc are blacker on a scan because they do not have as much water as a healthy disc), a disc bulge, or an annular tear (tear into the outer annulus of the disc space on a scan that shows up as a bright white spot).
There is a major question about all these studies. Are degenerated disks causative of low back pain? In the cervical spine, if degenerative disease is a cause of pain, it should be more frequent at older ages than 49, which is the peak time of incidence. Degenerative changes on cervical MRI do not correlate with neck pain, since these findings are commonly found in asymptomatic people.1
White arrow points to a degenerative L5-S1 disc, the most common level of degeneration in the lumbar spine. Blue arrow is the spinal cord, red arrow is cerebrospinal fluid, black arrow points to a healthy well hydrated L3-4 disc. Notice the normal bright signal in the center of the disc(T2 MRI water shows up as bright signal). Compare this to the dark disc at L5-S1 which is dehydrated and degenerative.
Disc degeneration is actually quite common among people who have no pain or other symptoms, so the patient's history and physical examination are an essential part of the diagnosis. Disc Degeneration at an early age is usually the result of repetitive microtrauma or cumulative traumatic episodes.
What should patients expect during the first six weeks and, if necessary, beyond?
Degenerative Disc Disease(DDD) is a gradual process that may compromise the spine. It needs to be managed just like other chronic diseases like diabetes or heart disease.
Non-Operative Treatment: Yesterday vs. Today
DDD is a disorder that may cause low back pain. It is interesting to note that although 80% of adults will experience back pain, only 1-2% will need lumbar spine surgery!
First Six Weeks
Usually during the first six weeks, acute low back pain treated with a couple of days of bed rest (slightly longer with a 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, 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.
Beyond Six Weeks
If the symptoms of degenerative disc disease and low back pain persist despite non-operative treatment, further diagnostic tests may be necessary. These tests may include an MRI, CT Scan, myelogram, or possibly discography.
Although most degenerative disc disease patients with herniation respond well to non-surgical treatment, a small percentage do not. Disc herniation causing motor weakness and arm or leg pain is the most common indication for spinal surgery. In fact, 75% of all spinal surgeries are for a herniated disc.
Red Flags
- Cervical Myelopathy: a condition of cervical spinal cord compression sometimes caused by severe degerative spondylosis in the neck. Symptoms include: hyperactive reflexes, unstable gait(ataxia).
- Motor weakness in the arms or legs.
- Radicular pain: pain shooting down arms or legs.
- Lumbar (low back) 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.
With cauda equine syndrome present, surgery is required immediately. However, most herniated discs often do not require surgical intervention and respond quite nicely to non-surgical treatments.
How is Degenerative Disc Disease treated
For most people, degenerative disc disease can be successfully treated with conservative (meaning non-surgical) care consisting of medication to control inflammation and pain (either oral or injection), joint manipulation, soft tissue treatment, and physical therapy and exercise. Surgery is only considered when patients have not achieved relief over six months of conservative care and/or are significantly constrained in performing everyday activities.
CONSERVATIVE CARE FOR DEGENERATIVE DISC DISEASE
A comprehensive treatment regimen should include the following:
1. Regional orthopedic/ neurological exam and biomechanical functional assessment to identify pathology and dysfunction.
2. Identifying and correcting the underlying muscle imbalance by manipulating scar tissue utilizing Active Release Techniques®.
3. Then completing a comprehensive rehab program to relearn motor firing patterns, increase core spinal stabilization, and correct for postural alterations.
4. Manual therapy when appropriate to restore normal joint biomechanics. This often times includes traction, either cervical or lumbar.
5. Sport specific training and ultimate return to normal form and function of sport specific activity if applicable.
CONSERVATIVE TREATMENT
The ongoing pain, as well as the frequency and intensity of flare ups, can be mitigated through a number of non-surgical options. Modifying activities to preclude or limit lifting of heavy objects and playing sports that require rotating the back (e.g. golf, basketball or football) can be a good first step. Other options include:
- o Applying contrast therapy to stiff muscles or joints to increase flexibility and range of motion. This is done by applying ice packs for 5-10 minutes to cool down sore muscles or numb the area where painful flares are concentrated, followed by 5-10 minutes of heat. This cycle is repeated 3-4 times, always ending with ice.
Active Care Treatment
Active Release Techniques® A.R.T. is done using a hands-on method of locating and correcting problem areas in and between soft tissues such as muscles, nerves and tendons. The main concept is to reestablish proper motion between fascial structures thus reducing fibrous adhesions and reestablishing neural and myofascial glide between tissues. The technique utilizes active patient motion whenever possible, a tension contact is used as opposed to compressive contacts used in other soft tissue techniques. The concept is simple; its just not easy.
Manipulation
Restoration of normal joint mechanics is essential before beginning a corrective exercise program.
A specialized treatment called Cox Flexion Distraction has been clinically proven to be effective in these cases. The concept is to achieve decompression of the lumbar spine and allow the joints to be stretched through all planes of motion to free up joint mobility.
Many cases of lumbar degenerative disc disease are effectively treated with lumbar traction and even home inversion table therapy.
Most cases in the cervical spine require therapeutic traction during the initial rehabilitation and physical therapy, followed by home cervical traction which allows the patient to continue to treat the disease daily at home.
Therapeutic Exercise
A corrective exercise program is essential to relieving the pain of lumbar degenerative disc disease and should have several components, including:
A functional movement Assessment to screen for muscle imbalance, restricted ROM of the muscles and joints, balance difficulty, and poor movement patterns. All of these put more stress into the body than should be.
Following the movement screen, stretches and exercises will be prescribed to :
Lengthen tight muscles using foam rollers, stretching, and soft tissue manipulation(ART). Once these tissues are lengthened, exercises will be prescribed to strengthen and activate weak muscles. As they become stronger, more advanced exercises will be progressively introduced to integrate functional movement and reinforce proper movement.
Low-impact aerobic conditioning (such as walking, swimming, biking) to ensure adequate flow of nutrients and blood to spine structures, and relieve pressure on the discs
For some patients extension exercises, such as the McKenzie method, are used. These focus on the muscles and ligaments of the lumbar spine. These exercises help maintain the spine's natural lordotic curve, important to good posture.
Swimming and biking(no/low impact) offer 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 exercise 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
Acupuncture, a type of alternative medicine, has been shown to help 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.
Drug Therapy
During the acute phase of low back pain, drugs may be prescribed. Some may include acetaminophen, anti-inflammatory agents, muscle relaxants, narcotics, and anti-depressants. Narcotics are used on a short-term basis partly 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.
Medications such as non-steroidal anti-inflammatories (e.g., ibuprofen, naproxen, COX-2 inhibitors) and pain relievers like acetaminophen (such as Tylenol) help many patients feel good enough to engage in regular activities. Stronger prescription medications such as oral steroids, muscle relaxants or narcotic pain medications may also be used to manage intense pain episodes on a short-term basis, and some patients may benefit from an epidural steroid injection. Not all medications are right for all patients, and patients will need to discuss side effects and possible factors that would preclude taking them with their physician.
Surgery for Degenerative Disc Disease
Surgical Procedures
The type of surgical procedure depends on the patient, the diagnosis, and the treatment goals.
Surgical removal of a disc may involve a limited laminotomy and partial disc excision. The disc fragments are removed and the nerve is decompressed. Microdiscectomy is often a preferred procedure requiring smaller incisions. Benefits include smaller scars and a faster recovery.
If the entire disc is removed, fusion may be needed to stabilize the spine. Patients who are obese, smoke, or who have psychological problems experience 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 (e.g. screws, cages).
While it is a major surgery, fusion surgery can be an effective option for patients to enhance their activity level and overall quality of life. This is particularly true now that minimally invasive techniques are available to decrease post-operative discomfort, preserve more of the normal anatomy of the low back, and result in higher rates of fusion than previous techniques.
A newer surgery to treat pain and disability from lumbar degenerative disc disease is artificial disc replacement. The theory is that replacing the disc, instead of fusing the disc space together, maintains more of the normal motion in the lumbar spine, thereby reducing the chance that adjacent levels of the spine will break down due to increased stress. This procedure is still a new procedure in the US, so long-term efficacy, and potential risks and complications are still relatively unknown.
For more detailed information on the latest spine surgical procedures go to
http://www.texasback.com/spinecare.htm
References
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- Guzman J, Haldeman S, Carroll LJ, Carragee EJ, et al. Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders. From Concepts and Findings to Recommendations. Spine, April2008;33(4S):S199-213.
