Background & Etiology
The intervertebral disc is a fibrocartilaginous structure found between the bodies of the vertebra. There is a disc between each pair of vertebra in the spine except for the first and second cervical level (atlas and axis).
The disc is similar to a jelly donut. It has a series of outer fibrous rings (annulus fibrosis) surrounding a gelatinous center (nucleus pulposus). The outer annular rings are thinnest posterior and lateral. Most disc herniations occur here due to the weakness of the disc wall. The disc functions as a cushion, allows for movement, and serves as a cartilaginous joint between adjacent vertebrae.
Inflammation, damage or degeneration of a disc can cause a range of symptoms that vary based on the severity of the problem. Disc pathology may produce a loss of back motion, back pain, radiating pain into the leg and the foot, numbness, tingling, lower extremity (leg) weakness and associated muscle spasm or some combination of these symptoms. The lumbar fourth and fifth (L4-L5), and lumbar fifth and sacrum (L5-S1) levels have the highest rate of disc degeneration and herniation.
Degenerative Disc Disease
Degenerative disc disease is not an actual disease but is the term used to describe the progression of changes, gradual wear and tear, and dysfunction associated with symptoms secondary to disc degeneration. Degeneration of the disc is normal with aging but can be accelerated in certain situations as a result of trauma, repetitive strain or injury and musculoskeletal imbalances like scoliosis. Disc degeneration itself is not a problem, but the associated conditions that may develop as it progresses can be symptomatic and debilitating.
Stages of Disc Degeneration
The progression of disc degeneration can be classified in the following phases:
- Tears of the annular rings of the disc with irritation of the facet joints at the corresponding spinal level may occur.
- There is loss of joint mobility, localized back pain, muscle spasm, and loss of movement especially extension or backward motions.
- Loss of disc fluid with dehydration and disc narrowing. The facet joints and capsule may develop laxity resulting in instability.
- A patient will present with pain, sharp catching, giving way, a shift in spinal alignment and loss of motion.
- The body reacts to the instability by laying down bone in the form of osteophytes to stabilize the spine. This increase in bone formation can result in Stenosis.
- Back pain will usually decrease, but remain present in a less severe form. Individuals may develop stenotic-like symptoms in the legs, with weakness and difficulty walking and standing for extended periods of time.
- Aging is the most common cause of disc degeneration. As the body ages the discs start to lose fluid and dehydrate. The discs start to narrow and lose their height, compromising their ability to absorb shock and stress.
- The outer fibrous annular rings may begin to crack and tear, weakening the disc walls.
- Individuals who smoke, are obese, and are involved in activities that require heavy labor are more likely to develop disc degeneration.
- Sudden fall or trauma to the spine or disc may begin the degenerative process.
- A disc herniation may initiate the stages of disc degeneration. Unlike muscles, there is minimal blood supply to the discs, so they lack reparative ability.
- Many times, people suffering from DDD do not show symptoms.
- When symptoms are present, chronic low back pain, with or without radiation to the hips, and aching pain in the buttocks or the backs of the thighs, may be seen with walking.
- Muscle spasm in the back, extending to the buttock area.
- Other symptoms include pain that is generally made worse with sitting, bending, lifting and twisting.
- Stenosis will develop in the later stages, with decreased ability to walk and stand for extended periods of time. Individuals can develop weakness, which may necessitate surgery.
Conditions of the intervertebral disc that can develop as a result of disc degeneration include bulging disc, herniated disc, prolapsed disc, degenerative disc disease, annular tear of the disc, ruptured disc and slipped disc.
Treatment of lumbar degenerative disc disease or injury will depend on the severity of the condition. When treating acute back problems:
- Rest: avoid the activities that produce the pain (bending, lifting, twisting, turning or bending backwards).
- Medication to reduce inflammation (anti-inflammatory drugs and pain medication).
- Ice in acute cases: apply ice to the lumbar spine to help reduce pain and associated muscle spasm. Apply it right away and then at intervals for about 20 minutes at a time. Do not apply directly to the skin.
- Moist heat may be helpful to reduce pain and improve any feelings of stiffness.
- An exercise regiment designed specifically to address the cause of the symptoms associated with the degenerative disc disease and improve joint mobility, spinal alignment, posture, and range of motion.
- Bracing or the use of supports may be necessary to reduce stress on the facet joints, muscles and lumbar spine.
- Steroidal medication to reduce inflammation in moderate to severe conditions.
- Epidural injections directly to the involved disc may be indicated.
- Physical therapy to reduce inflammation, restore joint function, improve motion, and help the return of full function.
In mild cases rest, ice and medication may be enough to reduce the pain. Many patients will do well with this regiment. Once the pain is reduced, physical therapy is recommended to develop a series of stretching and strengthening exercises to prevent reoccurrence of the injury. Return to activity should be gradual to prevent a flare up of symptoms.
Moderate to Severe
If the problem persists, consulting with your health care provider should be the next step. Your physician will perform a thorough evaluation to determine the possible cause of your symptoms, the structures involved, the severity of the condition, and the best course of treatment.
In addition to performing a thorough examination your physician may order the following tests to make a more concise diagnosis:
- X-ray to determine if there is any joint degeneration, fractures, bony malformations, arthritis, tumors or infection present.
- MRI to determine any soft tissue involvement including visualization of the discs, spinal cord and nerve roots.
- CT scans, which can give a cross section view of the spinal structures.
- EMG, which is used to determine nerve involvement or damage.
Your physician may recommend several medication options individually or in combination to reduce the pain, inflammation and muscle spasm that may be associated with disc injuries.
- Over the counter medications for mild to moderate pain.
- Narcotics, if over the counter medications are not effective your physician may prescribe stronger pain medication.
- Anti-inflammatory drugs or prescription NSAIDS to reduce inflammation following acute injury.
- Muscle relaxers to reduce acute muscle spasm.
- Nerve pain medication by prescription, designed specifically to reduce pain from nerve damage.
- Injections like facet injections, nerve blocks or an epidural. These may involve the injection of corticosteroids to a specific structure to reduce local inflammation.
Severe or Non-responsive Disc Degenerative Condition
In the case of conditions that do not respond to conservative care, surgery may be indicated. If you continue to experience some of the following symptoms:
- Increase in radiating or radicular pain
- Pain or nerve damage that gets worse
- The development of or an increase in weakness
- Increase in numbness or parasthesia
- Loss of bowel and bladder control
- Stenotic symptoms with the inability to stand or walk for extended periods of time and weakness of the lower extremities.
The most common disc related surgery is a discectomy in which the disc is removed through an incision. However, there are several other surgical interventions that may be indicated in the case of degenerative disc disease. Which procedure will be performed depends on the cause of the symptoms. Some examples include foraminotomy, laminotomy, spinal laminectomy, spinal decompression, and spinal fusion. Spinal surgery is not usually performed when the only symptom is back pain.
Physical Therapists are professionals, educated and trained to administer interventions. As defined by The Guide to Physical Therapist Practice, interventions are the skilled and purposeful use of physical therapy methods and techniques to produce changes consistent with the diagnosis, prognosis and the patient or client’s goals.
Your physical therapist will perform a thorough evaluation to assess and determine the following:
- Spinal Examination where the patient is put through a series of movements and tests to determine the most probable cause of the condition.
- Strength: resisted testing is performed to determine if there is associated weakness or strength imbalances.
- Flexibility: tight muscles can contribute to poor mechanics and weakness, thus creating imbalances and making one more susceptible to disc and back injuries.
- Posture Analysis, ADL’s and technique: discuss and observe the activity that may have started the problem. Examination of dynamic and static postures that may have caused or contributed to your current back problem. A review of your current activities at home and work that may or may not be causing or prolonging your present condition.
Physical therapy for back and degenerative disc problems must remain conservative at the onset to avoid aggravating the condition. Emphasis will be on rest, reducing the inflammation and increasing the blood circulation for healing. Once the initial inflammation has been reduced, a program of stretching and strengthening will be initiated to restore flexibility to the joints and muscles involved while improving strength and stability to the spine. Your program design will be based on the structure and cause of your symptoms. A program not tailored to your problem could aggravate your symptoms.
Common Physical Therapy interventions in the treatment of degenerative disc disease include:
- Manual Therapeutic Technique (MTT): hands on care including soft tissue massage, stretching and joint mobilization by a physical therapist to improve alignment, mobility and range of motion of the lumbar spine. Use of mobilization techniques also helps to modulate pain.
- Therapeutic Exercises (TE) including stretching and strengthening exercises to regain range of motion and strengthen muscles of the back and abdominals to support, stabilize and decrease the stresses place on the disc and back.
- Neuromuscular Re-education (NMR) to improve posture, restore stability, retrain the patient in proper sleeping, sitting and body mechanics to protect the injured disc and spine.
- Modalities including the use of ultrasound, electrical stimulation, ice, cold laser, traction and others to decrease pain and inflammation of spinal structures.
- Home programs including strengthening, stretching and stabilization exercises and instructions to help the person perform daily tasks and advance to the next functional level.
Most disc problems improve without surgery and return to normal function. Duration of treatment can range from 4 to 12 weeks depending on the severity of the symptoms. Patients need to continue with a regiment of stretching, strengthening and stabilization exercises. Use of proper mechanics, body mechanics and awareness of the do’s and don’ts for a healthy back is necessary for a good long-term prognosis. The attitude of, “once you have a back problem, you have a back problem” goes a long way to preventing further injury.