Lumbar Disc Herniation

by Marshall Berkeley

Description

Lumbar disc herniation is the result of the nucleus proposus rupturing through the annulus fibrosus and compressing on the spinal nerve, causing low back and/or leg pain. Upwards of 80 percent of the population will experience low back pain at some point in their lives.¹ Lumbar disc herniations are one of the main causes of low back pain. The following information will provide you with all the details necessary to gain a better understanding of the condition.

Anatomy

The lumbar spine consists of five vertebrae. Located between each of the five vertebrae are intervertebral discs. The discs are flexible and act as shock absorbers for the spine. The intervertebral discs are made up of two components: the annulus fibrosus and the nucleus proposus. The annulus fibrosus is the tough outer ring of the disc, and the nucleus proposus is the soft, gel-like substance in the middle of the disc. Located posteriorly to the intervertebral discs is the spinal canal in which the spinal cord passes through. At each level of the lumbar spine, nerve roots exit the spinal canal through intervetebral foramina on both sides of the vertebrae.^2,3

Incidence/Prevalence

Lumbar disc herniations are one of the most common causes of low back pain and occur 15 times more than cervical disc herniations. The peak occurrence is between the ages of 25-40.³ Males are affected more than women by a ratio of 3:2. About 90% of all lumbar disc herniations occur between the fourth and fifth lumbar vertebrae and fifth lumbar vertebrae and sacrum.⁴

Clinical Presentation

A patient with a lumbar disc herniation will complain of low back pain and sometimes pain in one or both of the legs. Most often, pain is reported on only one side of the low back and is considered a dull ache, burning pain, electric shock, or tingling sensation. The patient will not be able to sit for prolonged periods of time before they have to get up. Sneezing, coughing, and laughing will increase the pain. Leg pain, or sciatica, is common and will be located in the back of the thigh, calf, and/or foot depending on the extent of the nerve involvement. Numbness and weakness in the leg or foot may also be present. In serious cases, bowel and bladder control can be lost.

Potential Etiologies

Lumbar disc herniations can occur as a result of direct trauma or gradual degeneration over time. There are also several risk factors that can lead to a lumbar disc herniation.^1,2 These include:

• Gender (males more susceptible than females)
• Poor lifting technique (bending over and not using legs to lift)
• Poor posture (puts increased stress on lumbar spine and discs)
• Repetitive activities (jobs involving bending, twisting, lifting, or pulling)
• Frequent driving (sitting for long periods of time plus the vibration of engine)
• Sedentary lifestyle (lack of physical activity & poor nutrition lead to poor disc health)
• Overweight (puts more pressure on discs)
• Smoking (decreases oxygen supplied to discs)

Diagnostic Tests^3,5

• Magnetic Resonance Scan
• Computed Tomography (CT) scan
• Myelogram
• Electromyography (EMG)
• Nerve Conduction Velocity (NCV) test
• X-ray

Evaluation/Special Orthopedic Tests

• Straight Leg Raise or Slump Test to determine if neural tension is present
• Neurological exam if pain, numbness, or tingling is present in leg(s)⁶

Conservative Treatment

• Rest: important to avoid bending forward and lifting heavy objects
• Nonsteroidal anti-inflammatory drugs (NSAIDs): for pain relief
• Physical therapy: emphasis on core stabalization exercises
  • Robin McKenzie developed the McKenzie Method for classifying and treating spinal disorders⁷
    • classified disorders as either postural, dysfunction, or derangement
    • derangement is most common and involves "centralizing" the pain
    • focus on education and actively involving the patient in the treatment
    • an example of a McKenzie technique is shown in the following video:

• Epidural steroid injection: steroids are injected directly into the level of the lumbar spine where the herniation is present
  • provides a short-term reduction of inflammation
  • usually performed if other conservative treatments have not been effective
  • successful in 42%-56% of patients¹

Modalities

In addition to other conservative treatments, there are also several modalities that can be included in treatment for lumbar herniated discs. These include:

• Mechanical traction⁸
• Ultrasound⁸
• Low-Power Laser⁸

While these are proven to decrease symptoms associated with lumbar herniated discs, they should not soley be used as treatment.

Surgical Treatment

• Microdiscectomy: most common surgical procedure for herniated lumbar discs⁹
  • removes the piece of the disc and any other fragments that are compressing on the spinal nerve
  • more effective in relieving leg pain associated with the herniated disc than back pain
    • successful in relieving leg pain in >90% of patients¹⁰

Footnotes

1. American Academy of Orthopedic Surgeons. Lumbar Disk Herniation. http://orthoinfo.aaos.org/topic.cfm?topic=A00534. Updated February 2009. Accessed November 16, 2010.

2. Abibol J, Dawson E, Haid R. Lumbar Herniated Disc. http://www.spineuniverse.com/conditions/herniated-disc/lumbar-herniated-disc. Updated May 18, 2010. Accessed November 16, 2010.

3. Mayfield Clinic. Herniated lumbar disc. http://www.mayfieldclinic.com/PE-HLDisc.htm. Updated April 2009. Accessed November 16, 2010.

4. Ullrich P. Lumbar Herniated Disc. http://www.spine-health.com/conditions/herniated-disc/lumbar-herniated-disc. Updated July 22, 2009. Accessed November 16, 2010.

5. MedlinePlus. Herniated disk. http://www.nlm.nih.gov.proxymu.wrlc.org/medlineplus/ency/article/000442.htm. Updated May 25, 2010. Accessed November 16, 2010.

6. Humphreys S, Eck J. Clinical Evaluation and Treatment Options for Herniated Lumbar Disc. http://www.aafp.org/afp/990201ap/575.html. Updated February 1, 1999. Accessed November 16, 2010.

7. The McKenzie Institute International. The McKenzie Method. http://www.mckenziemdt.org/approach.cfm?section=int. Updated 2010. Accessed November 23, 2010.

8. Unlu Z, Tasci S, Tarhan S, Pabuscu Y, Islak S. Comparison of 3 physical therapy modalities for acute pain in lumbar disc herniation measured by clinical evaluation and magnetic resonance imaging. J Manipulative Physiol Ther. 2008;31(3):191-198.

9. Weinstein JN, Tosteson TD, Lurie JD, et al. Surgical vs nonoperative treatment for lumbar disk herniation: the Spine Patient Outcomes Research Trial (SPORT): a randomized trial. JAMA. 2006;296(20):2441-2450.

10. North American Spine Association. Herniated Lumbar Disc. http://www.spine.org/Documents/herniated_lumbar_disc_2006.pdf. Updated 2006. Accessed November 16, 2010.