Prolapsed Disc

Prolapsed Disc
By Tarun Jolly, MD, Ryan Cooper

As many as 84% of adults will experience low back pain during their lifetime stemming from a variety of potential problems with the spine and associated structures1. One possible cause of back pain is a prolapsed disc; a condition in which a portion of an inter-vertebral disc protrudes outside of its disc space2. A prolapsed disc is caused by trauma and/or repetitive strain to the spine and discs, as often occurs with heavy lifting or twisting4. Disc prolapse accounts for 5% of lower back pain cases and is one of the most common reasons for surgery7. Often, a prolapsed disc is referred to as a herniated or bulging disc; and although subtle differences exist between the conditions, diagnosis and treatment of related low back pain is typically the same.

Inter-vertebral discs lie between the bones surrounding the spinal cord, called vertebrae, which are stacked in a column to form the spine5. The spine protects the spinal cord, and the discs support the individual vertebrae and facilitate spinal motion. The inter-vertebral discs are composed of a thickened outer layer termed the annulus fibrosus and a liquid inner portion termed the nucleus pulposus6. A disc can be said to prolapsed when the innermost nucleus presses against the surrounding annulus causing some of it to bulge out of its normal space; when this protrusion compresses a spinal nerve root, it can cause a variety of symptoms including pain, numbness and weakness2, 3.

Prolapsed discs most frequently occur in the lumbar spine (lower back), however they can also occur in the cervical spine (neck) and rarely in the thoracic spine (upper back)4. If a prolapsed disc presses against a spinal nerve root in the lumbar spine, it can cause pain in the lower back and leg. This pain from nerve root compression is known as a radiculopathy5. Sometimes a radiculopathy can also cause numbness or weakness in the lower extremities and groin region, as well as bowel/bladder incontinence. Incontinence is often the sign of a more serious condition known as Cauda Equina syndrome, which is a surgical emergency1.

A doctor can diagnose a prolapsed disc after taking a proper history, performing a physical exam and ordering diagnostic imaging tests. Of the variety of diagnostic imaging tests, a doctor may order1, 6:

  • An X-Ray to rule out other possible causes of pain, including fracture
  • A Computed Tomography (CT) or Magnetic Resonance Imaging (MRI) scan to directly visualize the inter-vertebral disc s and any nerve root compression. This is sometimes done after injecting contrast material into the disc
  • Nerve conduction studies if there is difficulty isolating the affected nerve roots

A doctor usually will not order imaging studies to confirm a prolapsed disc until conservative treatments have failed and symptoms persist for more than four weeks, since 90% of patients experiencing low back pain will see improvement with general conservative treatment1, 7. Conservative treatment can include:

  • Physical therapy including general strengthening, spinal manipulation, hot/cold therapy, ultrasound therapy, brace support, traction and more8
  • Lifestyle changes including a balanced diet with moderate exercise to eliminate strain due to weight4
  • Over the counter non-steroidal anti-inflammatory medications (NSAIDS) such as aspirin, ibuprofen (Advil™) or naproxen (Aleve™) can be used for management of mild pain4
  • Short-term use of narcotic/opioid medications such as codeine and/or muscle relaxants can be prescribed for severe pain4
  • Epidural steroid injections have been shown to directly reduce inflammation associated with disc prolapse and nerve root compression yielding some benefit for pain4

Most individuals with a symptomatic prolapsed disc will not require additional intervention; however surgery may be indicated when conservative treatment fails to alleviate pain4. The reason for surgery with a prolapsed disc is to manually relieve the compression of any affected nerve or nerve roots7. The most common surgical interventions are7, 8:

  • The open discectomy; the gold standard surgical treatment for a prolapsed disc, in which portions of damaged disc can be removed via incision access to the spine to reduce pressure on affected nerve roots
  • The micro-discectomy; similar to the open discectomy, but incorporates the use of magnification with smaller incisions to excise damaged disc material
  • Advances in technology have also allowed for the development of more minimally invasive surgical techniques that incorporate devices such as lasers and endoscopes to improve recovery times

Post-surgery, it may take time before patients are able to resume normal activities; it is important for these patients to avoid certain strenuous activities to prevent recurrence4. Louisiana Pain Specialists can assist patients with a protruded disc in determining an appropriate course of treatment.

It’s possible to help prevent prolapsed discs before they happen, particularly by practicing good posture and proper lifting techniques, although this may not be possible when trauma is involved. Disc prolapse is primarily associated with heavy lifting; however there may be other risk factors as well, such as being male, having a congenital spinal defect, and engaging in strenuous physical activity4.

References:

  1. Wheeler, S.; et al. (2010). Approach to the diagnosis and evaluation of low back pain in adults. In: UpToDate, Basow, DS (Ed), UpToDate, Waltham, MA.
  2. eOrthopod. (2009). What’s the difference between a disc prolapse and a disc herniation? eOrthopod. Retrieved from www.eorthopod.com/content/whats-the-difference-between-a-disc-prolapse-and-a-disc-herniation
  3. Fardon, D.; Milette, P. (2001). Nomenclature and Classification of Lumbar Disc Pathology: Recommendations of the Combined Task Forces of the North American Spine Society, American Society of Spine Radiology, and American Society of Neuroradiology. Spine. Vol 26, E93-E113.
  4. Nidus Information Services. (2010). Herniated Disk. Patient Handouts page. MD Consult Web site, Core Collection. Retreived from www.mdconsult.com.ezproxy2.library.arizona.edu/das/patient/body/234155712-5
  5. Hsu, P.; et al. (2011) Lumbosacral radiculopathy: Pathophysiology, clinical features and diagnosis. In: UpToDate, Basow, DS (Ed), UpToDate, Waltham, MA.
  6. Raj, P. (2008). Intervertebral Disc: Anatomy-Physiology-Pathophysiology-Treatment. Pain Practice. Vol 8, 18-44.
  7. Gibson, J. N. A.; Waddell, G. (2007). Surgical Interventions for Lumbar Disc Prolapse. Spine. Vol 32 1735-1747.
  8. Chou, R. and Huffman, L.H. (2007). Nonpharmacologic therapies for acute and chronic low back pain: a review of the evidence for an American Pain Society/American College of Physicians clinical practice guideline. Ann Intern Med. Vol 147(7), 492-504.