Trauma and the Degenerated Spinal Discs

October 31, 2013

By Melissa D. Carter, Attorney at Law

A ‘Degenerative disc’ in the spine is natural and normal, when related to our ongoing aging processes, and frequently results in no symptoms or pain. A degenerative disc can also be the result of a traumatic injury that is associated with pain, weakness, loss of stability or other neurologic changes.  When trauma is superimposed on a pre-existing degenerative disc that was not causing pain, this can cause an awakening of the disc, resulting in pain and a more complicated healing process.  The impact this has on a personal injury claim can be profound.

General Background of Degenerative Disc Disease

A healthy, stable spine must be flexible and stable at the same time.  The key component to these characteristics of the spine is the ‘intervertebral’ disc: the disc that is in between the vertebrae above and below it.   We have cervical (neck), thoracic (mid-back), and lumbar (low-back) discs in the spine.  A disc is made up for four components: the outer annulus, the inner annulus, the transition zone and the central nucleus pulpous:

 The intervertebral disc, the vertebrae above and below it and the spinal ligaments, together comprise the “functional spinal unit.”  Within that unit, there are facet joints posteriorly (on the backside).  Together the facet joints and the disc support the compressed load at each level of the spine, known as the “three joint complex”:

The nucleus pulposus is the jelly-like substance in the middle of the disc.  It functions to distribute loading-pressure in all directions within each disc. The nucleus pulposus consists of chondrocyte-like cells, collagen fibrils, and proteoglycan aggrecans, which allow it to draw water into the nucleus pulposus.As we age, the intervertebral disc begins to degenerate and dehydrate after repetitive exposure to ordinary ‘wear and tear’ or mechanical loading.  The intervertebral disc in older spines has a smaller concentration of proteoglycans in the nucleus pulposus, causing a decreased ability to stay hydrated and an altered disc structure, often in the appearance of a thinner disc.  The inner annulus fibrosous then desiccates, causing the outer annulus fibrosous to deteriorate, leading to a loss of overall structure of the functional spinal unit.  Over time, degeneration can lead to disc bulges, protrusions and extrusions.[1]Trauma on the Degenerative SpineTrauma, no matter how mild, has the potential of aggravating or worsening a pre-existing degenerative disease of the spine.  Even those individuals with completely asymptomatic and pain-free degenerative discs are at risk of a significant “lighting up” of an otherwise dormant condition when trauma is superimposed on this condition.

When trauma occurs and the discs are healthy, ligaments are overstretched and strain is put on muscles, leading to tearing of muscle fibers and traumatization of the facet joint surfaces. The trauma promotes local buildup of inflammation and pain in the acute phase. The acute response to injury gradually resolves and the pain begins to lessen.   There is a different process at work, however, when trauma is superimposed on a degenerative disc.   In the presence of a degenerated disc, the effect of trauma goes beyond acute soft-tissue injury and includes symptoms from the degenerated joint / spine.  Residual symptoms in the vast majority of these cases are due to trauma that lights up (or makes symptomatic) the degenerative disc and thereby preventing resolution, or from damage to the cartilage on the surface of the facet part of the vertebrae.  The “high incidence of cervical osteoarthritis and spondylosis observed in those presenting years after trauma induced acceleration/deceleration injuries suggests a very strong causal relationship, especially when the disease is localized to one or two levels”.[2]

The Effects of “Pre-Existing Degenerative Disc Disease” on the Personal Injury Claim

In the context of a personal injury claim resulting from trauma, such as from a motor vehicle collision or a fall, when the injured person has a “pre-existing” degenerative disc that was asymptomatic, they likely will need more treatment for a longer period of time following the traumatic injury. Those people are also likely to have a poorer prognosis for a full recovery and are pre-disposed to a higher incidence of spondylosis in the future. This does not mean that insurers will accept this, however.  Insurers will try to reduce the value of a personal injury claim by hiring insurance medical examiners (IME) to argue that the ongoing residuals of the trauma are related to the underlying pre-existing degenerative processes.   In other words, if a patient with underlying degenerative changes in the neck or back suffers an injury and fails to recover from initial acute symptoms, the insurance-hired doctor will argue that the continuation of symptoms is from the underlying and pre-existing degenerative disc and not related to the traumatic event.

Fortunately, Washington law protects those individuals with a dormant condition that has been aggravated by trauma.  When a triggering event “lights up” and makes an inactive pre-existing condition into an active and symptomatic one, then that pre-existing condition cannot be a barrier to the injured person’s recovery against the negligent party who caused the traumatic injury.

[1] See Roh, ‘Degenerative Disorders of the Lumbar and Cervical Spine” Orthop Clin N. Am 36 (2005) 255-262
[2] Foreman Stephen M., Croft Arthur C. Whiplash Injuries: The Cervical Acceleration/Deceleration Syndrome. 2nd ed. Philadelphia, Lippincott Williams and Wilkins, 1995 p-340