By Ray Wiegand, DC; Mark Studin DC, FASBE(C), DAAPM, DAAMLP; and Kenneth M. Bahoora DC
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Editorial Note: The term “alteration of motion segment integrity” or AOMSI, refers to the loss of range of motion between two vertebrae that is beyond what one would consider “normal limits.”
In the following feature, the authors address AOMSI as a potential injury that the legal community may be faced with defending or explaining. Presented with a deep appreciation and understanding for the intricacies of their field, the article provides a professional, in-depth look at the issue for our readers. ~VLM
Alteration of motion segment integrity (AOMSI) is a biomechanical analysis. It’s all about numbers that have clinical meaning and significance. Threshold values have been determined that quantify without a doubt the patient has serious injury. It is a test of structural integrity of the ligaments interconnecting the motion segments. In this case, structural integrity has to do with the material properties of ligament tissue. Those properties include strength and flexibility. When a material is both strong and flexible, it’s called a semi-rigid material. Strength is related to the composition of the material. Strength might be thought of as load carrying capacity before failure.
Ligament tissue has previously been bench tested to describe its physical characteristics of stress/strain. That is, given so much load (stress), how much elongation will occur (strain)? During normal physiologic loads, the ligament remains intact and recoils to its original length when the load is removed. If the load becomes too large, the materials (ligaments) begin to yield. They go past their elastic limit. When this happens, the (strained) ligament fibers will not return to their original shape. The ligament loses its restraining capacity to hold the joint in normal stabilization and hypermobility occurs.
The ligaments, if sufficiently strained or avulsed, result in AOMSI. The following paragraphs illustrate that if AOMSI is found, there must be gross destruction or yielding of multiple ligaments.
The White et al. work found that the motion segment stayed intact (i.e., less than 11 degrees’ rotation (angular motion) and less than 3.5 mm translation) until they transected over 50 percent of the ligaments from an anterior or posterior approach. And when they transected from either approach, the loss of stability was not linear but suddenly catastrophic. And they meant that suddenly, the two vertebrae totally separated in rotation or translation.
In this case, “suddenly separated” means pulled apart—head off of body—with all neural components compromised. Paralysis. Keeping that in mind, what are the injuries of someone just under the threshold? Severe to very severe. They stand the possibility of a serious event with much less force.
If AOMSI is detected, think about more than 50 percent of ligaments being transected. That will start to explain the seriousness of the finding. In a patient/child that demonstrates hypermobility everywhere, you take a statistical average of all segments and look at the aberrant statistical finding if it exists. There are clues to injury everywhere when you understand what the numbers mean in reference to stability and function.
To diagnose ligament laxity, it is imperative that imaging be performed. A basic flexion-extension x-ray is all that is required. In today’s medical economy, advanced imaging like an MRI or CT scan, although accurate, becomes an unnecessary expenditure where an x-ray renders very accurate, demonstrative images to conclude a definitive diagnosis. In determining if there is impairment, it is necessary to follow the AMA Guides to the Evaluation of Permanent Impairment as the 4th, 5th and 6th editions all render impairment for AOMSI as sequella to ligament laxity, which is damage to the ligament from trauma.
This article is intended to serve as a simple explanation as to the severity of ligament damage and how to demonstrably diagnose the injury. It is also critical to remember that ligaments do “wound repair.” In normal physiology, ligaments grow during puberty from cells within the ligaments called fibroblasts. They produce both collagen (white) and elastin (yellow) tissue, which gives the ligaments both tensile and elastic strength. Upon puberty, the cells stop producing tissue and remain dormant. Upon injury, the fibroblast reactivates, but can only produce collage leaving the joint wound repaired in an aberrant juxtaposition (place) with poor movement abilities due to the lack of the requisite elastin. In turn, according to Hauser et al. (2013) this leads to permanent loss of function of the ligament and arthritis of the joint. This is not a speculative statement: it is based upon Wolff’s Law that dates back to the late 1800s and has been a guiding principle in healthcare for more than a century. According to the American Academy of Orthopedic Surgery, “The most common soft tissues injured are muscles, tendons, and ligaments. Acute injuries are caused by a sudden trauma, such as a fall, twist, or blow to the body. Examples of an acute injury include sprains, strains, and contusions.”
We must also not forget that there are other soft tissues that can get injured, and that the true definition of soft tissue is anything that is not bone. This includes the brain, lungs, heart, and any other organ in the body. However, in medicine soft-tissue injuries are commonly known to be limited to the muscles, ligaments and tendons.
When we look at the type of structures that muscles, tendons and ligament are composed of, we realize that they are connective tissue. According to the National Institute of Health, “Connective tissue is the material inside your body that supports many of its parts. It is the ‘cellular glue’ that gives your tissues their shape and helps keep them strong. It also helps some of your tissues do their work. Unlike fracture repair where the bone is replaced and usually heals properly if aligned and rested, connective tissue disorders undergo a different type of wound repair that has aberrant tissue replacement as sequella to bodily injury and has subsequent abnormal permanent function.”
If we focus on sprains or ligamentous injuries, according to the American Academy of Orthopedic Surgery, there are three types of sprains, which are classified by severity:(1)
• Grade 1 sprain (mild): Slight stretching and some damage to the fibers (fibrils) of the ligament.
• Grade 2 sprain (moderate): Partial tearing of the ligament. There is abnormal looseness (laxity) in the joint when it is moved in certain ways.
• Grade 3 sprain (severe): Complete tear of the ligament. This causes significant instability and makes the joint nonfunctional.
Regardless of the severity of the sprain, there is tissue damage or bodily injury, and the next step is to determine if there is healing or wound repair. According to Woo, Hildebrand, Watanabe, Fenwick, Papageorgiou and Wang (1999), “…as a result the combination of cell therapy with growth factor therapy may offer new avenues to improve the healing of ligament and tendon. Of course, specific recommendations regarding growth factor selection, and timing and method of application cannot be made at this time. Previous attempts at determining optimal doses of growth factors have provided contradictory results. Although growth factor treatment has been shown to improve the properties of healing ligaments and tendons, these properties do not reach the level of the uninjured tissue.” (p. s320)
According to Dozer and Dupree (2005), “No treatment currently exists to restore an injured tendon or ligament to its normal condition.” (p. 231)
According to Hauser, Dolan, Phillips, Newlin, Moore and Woldin (2013), “injured ligament structure is replaced with tissue that is grossly, histologically, biochemically and biomechanically similar to scar tissue. Fully remodeled scar tissue remains grossly, microscopically and functionally different from normal tissues” (p. 6), and “the persisting abnormalities present in the remodeled ligament matrix can have profound implications on joint biomechanics, depending on the functional demands placed on the tissue. Since remodeled ligament tissue is morphologically and mechanically inferior to normal ligament tissue, ligament laxity results, causing functional disability of the affected joints and a predisposing other soft tissues in and around the joints further damage.” (p.7) “Studies of healing ligaments have consistently shown that certain ligaments do not heal independently following rupture, and those that didn’t feel, do so characteristically inferior compositional properties compared with normal tissue. It is not uncommon for more than one ligament undergo injury during a single traumatic event.” (p.8) “Osteoarthritis for joint degeneration is one of the most common consequences of ligament laxity. Traditionally, the pathophysiology of osteoarthritis was thought to be due of aging and wear and tear on the joint, but more recent studies have shown that ligaments play a critical role in the development of osteoarthritis. Osteoarthritis begins when one or more of ligaments become unstable or lax, and the bones began to track improperly and put pressure on different areas, resulting in the rubbing the bone on cartilage. This causes breakdown of cartilage and ultimately leads to deterioration, whereby the joint is reduced to bone on bone, a mechanical problem of the joint that leads to abnormality of the joints mechanics. Hypomobility and ligament laxity have become clear risk factors for the prevalence of osteoarthritis.” (p.9)
Looking globally at the research over the last 16 years, in 1999, it was concluded that the most current treatments to repair or heal the injured ligament do not reach the level of the uninjured tissue. In 2005, it was concluded that no treatment currently exists to restore an injured tendon or ligament to its normal condition. In addition the current standard of ligament research, in 2013 it was concluded that ligaments do not feel independently, but damage ligaments are a direct cause of osteoarthritis and biomechanical dysfunction (abnormality of joint mechanics). The latest research has also concluded that ligament damage or sprains is the key element in osteoarthritis and not simply aging or wear and tear on the joint.
Thus, it is now clear based upon the scientific evidence that a soft-tissue injury is a connective tissue disorder that has permanent negative sequella, and is the cause of future arthritis. This is no longer a debatable issue, and those in the medical legal forum who are still arguing “transient soft tissue injuries” are simply rendering rhetoric out of ignorance and a possible ulterior motive because the facts clearly delineate the negative sequella based upon decades of multiple scientific conclusions.
The caveat to this argument is that although there is irrefutable bodily injury with clear permanent sequella, does it also cause permanent functional loss in every scenario? Those are two separate issues and as a result of the function of ligaments, which is to connect bones to bones the arbiter for normal vs. abnormal function is ranges of motion of the joint. That can be accomplished by either a two-piece inclinometer for the spine, which per the American Medical Association Guides to the Evaluation of Permanent Impairment, 5th Edition (p. 400), is the standard (and is still the medical standard as the 6th Edition refers to the 5th for Ranges of motion).
The other diagnostic demonstrable evidence to conclude aberrant function is to conclude laxity of ligaments through x-ray digitizing. Both diagnostic tools confirm demonstrably loss of function of the spinal joints.
1. Sprains, Strains and Other Soft Tissue Injuries (2015) American Academy of Orthopedic Surgery, Retrieved from: http://orthoinfo.aaos.org/topic.cfm?topic=A00111
2. Connective Tissue Disorders (2015) National Institute of Health, Retrieved from: http://www.nlm.nih.gov/medlineplus/connectivetissuedisorders.html
3. Woo S, Hildebrand K., Watanabe N., Fenwick J., Papageorgiou C., Wang J. (1999) Tissue Engineering of Ligament and Tendon Healing, Clinical Orthopedics and Related Research 367S pgs. S312-S323
4.Tozer S., Duprez D. (2005) Tendon and Ligament: Development, Repair and Disease, Birth Defects Research (part C) 75:226-236
5. Hauser R., Dolan E., Phillips H., Newlin A., Moore R. and B. Woldin (2013) Ligament Injury and Healing: A Review of Current Clinical Diagnostics and Therapeutics, The Open Rehabilitation Journal (6) 1-20
6. Cocchiarella L., Anderson G., (2001) Guides to the Evaluation of Permanent Impairment, 5th Edition, Chicago IL, AMA Press
7. White et al. Clin Ortho Relat Res, 1975;(109):85-96
8. Hauser et al. Dolan, Phillips, Newlin, Moore Woldin, B.A.(2013) Ligament injury and healing: A review of current clinical diagnostics and therapeutics. The Open Rehabilitation Journal, 6,1-20.
Dr. Kenneth Bahoora has been a treating physician in Nevada and for 17 years. He graduated from Life University in Atlanta Georgia where he received his diploma as a doctor of chiropractic. He is credentialed and received specialized knowledge in accident reconstruction, spinal biomechanical engineering, spinal MRI interpretation, MRI physics, providing impairment ratings utilizing AMA Guides (5th & 6th Editions), examining and triaging the trauma patient and neurodiagnostic interpretation protocols. He lectures to doctors and the legal community on subjects including but not limited to trauma and injury protocols and crash dynamics and the trauma victim. He can be reached for further explanation at firstname.lastname@example.org or at 702-204-4240.
Dr. Mark Studin teaches at the doctoral level as an adjunct assistant professor of chiropractic at the University of Bridgeport, College of Chiropractic, and an adjunct assistant professor of clinical sciences at Texas Chiropractic College. He also teaches at the graduate medical level as a clinical presenter credentialed by the Accreditation Council for Continuing Medical Education in Joint Sponsorship with the State University of New York at Buffalo, School of Medicine and Biomedical Sciences along with being credentialed nationally for chiropractic post-doctoral education in a broad range of clinical subjects. He can be reached at DrMark@AcademyofChiropractic.com or at 631-786-4253.