Background & Etiology
Intervertebral Disc – An intervertebral disc is a fibrocartilaginous structure found between the bodies of vertebra. These discs are located between each pair of vertebra in the spine except for those at the first and second cervical level (called 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 at this location 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, which vary based on the severity of the problem. Disc pathology may produce a loss of back motion, back pain, pain that radiates into the leg and foot, numbness, tingling, lower extremity (leg) weakness and associated muscle spasm or some combination of these symptoms. The lumbar levels with the highest rate of disc degeneration and herniation are the fourth and fifth (L4-L5), and lumbar fifth and sacrum (L5-S1) levels.
Degenerative disc disease
Anular tear of the disc
A disc herniation occurs when the outer walls of the intervertebral disc are torn. Other terms for this condition are ruptured disc, prolapsed disc, or slipped disc. When outer annular rings are torn the central gel-like nucleus pulposus can push out and place pressure on the other structures in the area. The herniation usually occurs at the posterior lateral wall where the annulus fibrosis is thinnest. Unfortunately this is where the nerves of the spine exit and track distally into the body. The larger the tear, and the further the nucleus pushes out into the surrounding area, the more severe the symptoms.
- Degeneration or general wear and tear, which can break down the walls of the disc.
- Repetitive bending and twisting motions especially in combination. This motion places the most stress on the outer fibrous rings.
- Discs are most susceptible to injury in the sitting or bending position as the pressure on the disc is displaced to the front (anteriorly) pushing the contents of the disc posterior laterally toward the thinner and weaker annulus fibrosis.
- Sudden fall or trauma like a motor vehicle accident.
- Genetic factors may contribute to the likelihood of intervertebral disc disease.
- Smokers are more susceptible to disc herniation and degeneration.
When a disc is herniated the symptoms will depend on the location of the herniation and what soft tissue structures are affected. Symptoms can vary from none at all or very mild if the disc is the only structure involved, or can be more severe. Other symptoms can include:
- Pain in the back or radicular to the buttock into the leg down to the foot if the disc presses on the nerve root.
- Sensory changes like numbness, tingling, or paraesthesia if the nerve is compromised.
- Weakness can occur if the motor portion of the nerve is effected by the disc’s condition. In severe cases paralysis may even occur.
- Diminished reflexes.
- Muscle spasm and changes in posture in response to the injury.
- Loss of motion including inability to bend or stand straight, and poor tolerance to sitting.
- Standing and walking can be difficult if the herniation is severe. Often the patient will present with a shifted posture and have difficulty finding a comfortable position
- A patient with a herniation may be symptom free if the disc does not press on a sensitive soft tissue structure.
Treatment of a disc herniation or injury will depend on the severity of the condition. When treating acute disc or back problems treatment options include:
- Rest: avoid the activities that produce the pain like bending, twisting, lifting and prolonged sitting.
- Medication to reduce inflammation (anti-inflammatory and pain medication).
- Ice: apply ice to the lumbar spine to help reduce pain and associated muscle spasm. Apply ice right away and then at intervals for about 20 minutes at a time. Do not apply directly to the skin.
- An exercise regiment designed specifically to address the cause of the symptoms.
- Bracing or the use of supports may be necessary to reduce stress on the disc, muscles and lumbar spine.
Mild: 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 precise diagnosis:
- X-ray to determine if there is any joint degeneration, fractures, bony malformations, arthritis, tumors or infections 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.
- Myelogram, which involves the injection of dye into the spinal column followed by an X-ray to visualize the position of and the pressure being applied to the discs.
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.
- If over the counter medications are not effective your physician may recommend stronger prescription pain medication.
- Anti-inflammatory drugs or prescription NSAIDS (non-steroidal anti-inflammatory drugs) to reduce inflammation following acute injury.
- Muscle relaxers to reduce acute muscle spasm.
- Prescription nerve pain medication designed specifically to reduce nerve damage and pain
- Injections such as facet injections, nerve blocks or epidural injections. These may involve the injection of corticosteroids to a specific structure to reduce local inflammation.
Severe or non-responsive disc condition
In the case of conditions that do not respond to conservative care, surgery may be recommended. If you continue to experience some of the following symptoms, your doctor may recommend you for a surgical procedure:
- Increase in radiating or radicular pain
- Pain or nerve damage that gets worse
- The development of increased weakness
- An increase in numbness or paraesthesia
- Loss of bowel and bladder control
The most common disc related surgery is a discectomy in which the disc is removed through an incision. It is done to remove leg pain. Disc surgery is typically not performed when there is only 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: the patient is put through a series of movements and tests to determine the most probable cause of the back pain.
- 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 creating imbalances and making one more susceptible to disc and back injuries.
- Posture analysis, ADL’s and technique: a physical therapist will 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 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 of the spine. Each program design will be based on the structure causing the problem and symptoms. A program not tailored to the specific problem may aggravate symptoms.
Common Physical Therapy interventions in the treatment of Lumbar Spine Disc Herniation 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 help 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 Reeducation (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 the spinal structures.
- Home programs including strengthening, stretching and stabilization exercises and instructions to help in the performance of daily tasks and progress 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 body mechanics and awareness of the do’s and don’ts for having a healthy back are necessary for a good long-term prognosis. Remember, “once you have a back problem, you have a back problem” goes a long way to preventing further injury.