Academy of Chiropractic’s Lawyers PI Program

Lawyers Meeting #16
Clinical Information #CI 3

From the Desk of :

“Herniated Discs from Trauma: The Research”

I have been asked many times to supply the exact citation, chapter and verse on where it says in the research that herniation is solely from trauma.  

This statement sets up the correct answer:

"Nor is there any need to assume that a disc must be degenerated before it can herniate. Herniation can be created in cadaveric tissues, either as a sudden injury or by a wear-and-tear (‘fatigue’) process, suggesting that herniation can be a physical process driven by excessive mechanical loading. However, the fact that many patients report no injury before the onset of sciatica suggests that some discs are more susceptible to herniation than others, probably on account of the weakening
effects of middle age10 or genetic factors."

1.      Reference: Lama, P., Le Maitre, C. L., Dolan, P., Tarlton, J. F., Harding, I. J., & Adams, M. A. (2013).  Do intervertebral discs degenerate before they herniate, or after? The Bone & Joint Journal, 95-B(8),1127–33.

Dr. Bill Owens and I have created the most concise answer that requires intimate knowledge of the research and the physiology.

“The true description and the causation of disc herniation will not ever directly be found in the research, but the information that we need to determine what happened to a particular patient is there. We have talked about that from day one. The information in the bi-monthly fliers is designed to create a dialogue, which then can be explained on a patient by patient basis. We have never at the beginning nor do we know state that there is a blanket statement that will cover all aspects of every patient and the lawyers will tell you that we  need to take the patient as they come and assess them on an individual basis.  In fact, truth be told I would NEVER want a single paper published that would be all encompassing, the human body and its response to trauma is too complex for that.  

With that being said, we do know that degeneration of the intervertebral disk results in a circumferential tear while a herniation results in a radial tear that is a proven fact. The argument that lawyers are trying to make but don't understand is the difference between morphology and etiology. Those are two completely different things, however the description of both of those terms will better clarify our position on the causation of disc herniation versus disc bulge. Morphology as we know is the physical description of the disc material while etiology is a description of the CAUSE of those changes.  We know that from the 2001 neuroradiology article on lumbar disk morphology that there are a myriad of descriptions of the shape, size and evolution of disc either from trauma or from degeneration, which is where 99% of the discussion on disc occurs, at morphology.  Where we rein that in is by using the disc definition slides from the 2001 article.  That is the highest level of authority on disc morphology.  

2.      Reference: Fardon, D. F., & Milette, P. C. (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, 26(5), p. E93–E113.

Etiology or causation has only TWO descriptive terms, and they are either a degenerative process or a traumatic process. The most recent paper that is reference clearly outlines the traumatic nature of disc injury either as a series of repetitive injuries or a single trauma (read reference #1). That is consistent with our teaching from day one.  It also describes the state of the disk before the repetitive or single traumatic event causing herniation. The argument that this paper was sorting out was that a disk has to be degenerative/old/weak in order for herniation to occur, which clearly based on the results of this paper does not have to be in place. So what this means is that a healthy strong disk can be injured due to repetitive event or single traumatic event.  So we now know that there is a distinct different between CAUSE and APPEARANCE and that CAUSE AND APPEARANCE can correlated with one another – AKA Trauma Herniation and Degeneration Bulge.

So how do we determine whether or not the disc herniated because of a single traumatic event or a series of repetitious events?  We then have to look at the body's natural response to alteration of motion segment integrity. We know from the Chinese engineering study that the piezoelectric effect will start to show progression at the six-month period (read reference #3).  As you know that's when we get osteophyte formation, endplate changes which then result in Modic changes and all of the visual effects of spinal degeneration. Most of this is due to changes in disc angle and translational forces. If the herniation was due to a repetitive event over time, we will encounter these degenerative type changes since the repetition is what resulted in the radial tear. The radial tear was initially not significant enough to reach the outer ring of the annulus, it happened interiorly overtime and progressed. The truth however is that it was due to single repetitive traumatic events although repetitive, there were individual traumatic events. That is often confused with degeneration, which is it is not a single traumatic event, therefore there is no radial tear.  The forces sustained were significant enough to create a radial tear from the nucleus pulposus to the outer edge of the annulus is what we would visualize on MRI.

3.      He, G., & Xinghua, Z. (2006). The numerical simulation of osteophyte formation on the edge of the vertebral body using quantitative bone remodeling theory.Joint Bone Spine, 73(1), 95-101.

So the statement disc herniation caused by trauma, and disc bulge caused by degeneration are 100% true and factual. The breakdown in the philosophical argument should it occur results from the argument of a single traumatic event for disk herniation or multiple traumatic events.  We know then based on the patient's history, and surrounding degenerative changes on the plain film x-ray and or MRI of the timing of the event. That's how we can time data disc herniation.  So we know that the herniation occurred due to trauma and we can factually state the timing of the event due to osteophyte disc complex formation.  Disc material PAST the osteophyte OR disc material in a different VECTOR when compared to the osteophyte.   

In a healthy disc, herniations will only generate pain when the outer third of the annulus is compromised, that's why the radial tear has to completely tear from the nucleus proposes to the outer edge. That is why you can have an asymptomatic radial tear.  In repetitive traumatic events over time as the radial tear progresses the disc will start the degeneration as a response. We know that that the degenerative response creates increased nerve fibers ingrowth to the annulus and nucleus (read reference #4). So in those cases a partial herniation or better said a radial tear that is not made it to the outer edge of the annulus will also be a competent producing source of pain because of the increased enervation.  

4.    García-Cosamalón, J., del Valle, M. E.,  Calavia, M. G.,  García-Suárez, O., López-Muñiz, A., Otero, J.,  & Vega, J. A. (2010).Intervertebral disc, sensory nerves and neurotrophins: Who is who in discogenic pain? Journal of Anatomy, 217(1), 1-15.

This bulges are easy because of the morphological description and the simple fact that separation of the annular lamina (as in circumferential separation, we need to stop using TEAR as it is confusion) occurs due to the breakdown of the disc material not from alteration of motion segment integrity.”