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A Real Pain In The Neck - Cervical Instability

instability research whiplash Aug 07, 2023
Instability (AOMSI)


Would you believe me if I told you that the past 100 MTBI cases we reviewed were incorrectly diagnosed? Probably not. But what is scary is that it's true.   

In response to frequent inquiries from my patients, other doctors, and attorneys about ligament injuries, I decided to discuss this topic today. The legal world often encounters cases where both defendants and plaintiffs seek to understand why ligament injuries are permanent. This knowledge is essential, not just for those in the insurance and legal fields but also for anyone interested in understanding the severity and long-term effects of ligament injuries. It's crucial to recognize that ligamentous injuries can result in chronic problems for patients. 

Understanding the specific damage that occurred is vital to accurately treat the individual. Often, people underestimate the severity of injuries such as whiplash, assuming they are self-resolving. The reality is that these injuries can be more insidious and long-lasting than most people imagine. Therefore, doctors need to prepare for short-term and long-term treatment plans using the most effective therapies available. 

My Experience: 

I have treated THOUSANDS of patients that have been in a whiplash accident and many of them are clueless as to the severity of the issue. Sadly, I would estimate that 95% of doctors don’t fully understand instability, how to diagnose it, how to treat it, and the long-term impacts of it. I say this because I have coached hundreds of doctors on instability cases that have been referred to me because the patient wasn’t improving and within a short period, we were able to get the patient on the right treatment path.  

After reviewing thousands of medical records and consulting with hundreds of paralegals regarding medical diagnoses, I've identified a common issue that arises when discussing whiplash injuries with insurance companies. Their responses often undermine the seriousness of the condition. Here are some typical comments from insurance representatives: 

  • “Oh, it's just a self-resolving issue.” 
  • “Yeah, they should be okay.” 
  • “They didn't break a bone.” 
  • “They are going to be alright.” 
  • “They sprained their neck (trying to downplay the severity). “ 
  • “They weren't even going fast enough for a whiplash injury. (I’ll discuss this more)” 
  • “There isn’t even any vehicle damage. There’s no way they could have been injured.” 

If you have heard some of these statements when negotiating, buckle up, and let’s discuss ligament instability. 

The Facts: 

Acute and subacute injuries such as whiplash resolve within six months for approximately 66% of patients with proper treatment. However, one-third of such cases develop into chronic problems, leading to enduring pain, even after six months. Thus, 1 in 3 individuals involved in motor vehicle accidents suffers from persistent, lifelong pain - a significant proportion considering the number of accidents that occur in the United States. I found useful information about this subject in the AMA guides, specifically on page 392 in the fifth edition, discussing a category 4 impairment rating, which refers to ligament injury. 

The severity of injuries can't be accurately measured based solely on speed or car damage, contrary to what some might think. In my experience, I have seen instability resulting from accidents as slow as 7 mph. In this case, the neurosurgeon I worked with didn’t even believe me till I showed him evidence of the injury. He was mind blown about the severity at such a low velocity. It's crucial to have a scientific, evidence-based perspective when dealing with such questions. Therefore, we aim to shed light on the underlying science, rather than resorting to opinion-based arguments. 

One study we found particularly revealing, was published in the Open Orthopedics Journal in 2014 written by Danielle Stilen. This study indicates that 5% of patients with whiplash injuries develop a significant disability and reduced quality of life. Considering the number of car accidents, 5% translates into a substantial number of people. 

For this group of patients, modern medicine often fails to provide long-term recovery options, suggesting the importance of understanding the exact nature of their injuries to offer effective treatment. Standard treatments for acute and subacute neck pain are well-established, but for chronic neck pain, conventional treatments are still debated. These may include: 

  • Over-the-counter medications 
  • Physiotherapy 
  • Manual therapy 
  • Exercises 
  • Nerve blocks 

However, these treatments often prove inadequate for chronic neck pain patients. 

The study also discusses various conditions related to whiplash-associated disorder or WAD, such as cervical instability, Baret-Lieu syndrome, concussion, and post-traumatic stress disorder. It's important to distinguish between these issues and understand the damage that has occurred to provide effective and targeted treatment. 

Anatomy 101: 

To fully understand what is going on, let’s discuss anatomy a bit. The upper cervical spine comprises the C0, C1, and C2 vertebrae, and the lower cervical spine consists of the C3 to C7 vertebrae. The upper cervical spine has no discs; it's all ligament. The ligaments hold the bones together and when damaged, as in the case of ligament laxity, can cause significant, long-term issues. In fact, studies show that damage to these ligaments can lead to increased degradation of a joint over the next five years by up to 500%! 

The focus of the aforementioned study was on the strength and durability of cervical capsular ligaments. The study underscores how robust these ligaments are - they are highly resistant, like the fibrotic tissue I've encountered during cadaver dissections. When I examine a patient with cervical flexion or extension in an X-ray, and see the bones slipping, I know there's extensive damage to the ligaments beyond their normal limit. In these situations, it's not just a matter of angular or translational instability, it's about the ligaments being damaged beyond the body's capability to repair. 

When a ligament is damaged beyond the body's elastic limit, it loses the ability to recoil and return to its original shape. For instance, if the anterior longitudinal ligament pulls away, a space is created, leading to the growth of bones and further development of osteophytes and degeneration. This degeneration triggers calcium ions to migrate to the affected area, causing more damage to the disc area. 

As this degenerative process continues, the anatomy of the joint changes due to a lack of synovial fluid, leading to morphing of the joint due to inflammation and the healing process. This results in bone degeneration, which causes aberrant motion and more degeneration. One of the key symptoms a person will feel is chronic pain. 

Any doctors, students, or attorneys dealing with such a situation must understand the importance of analyzing the ligament side of a cervical spine injury, especially when neck pain persists past three to six months. Ignoring this may result in misdiagnosis and an ineffective treatment plan, which could be considered a failure as a practitioner. 

How to Diagnose and What to Look For: 

I recall a patient who was in a bus accident. He was looking down at his phone when the bus had to abruptly stop, causing his head to slam into the seat in front of him, resulting in instant pain and a severe headache. His doctors misinterpreted the mechanism and extent of his injury, leading to improper care.  

The doctors prescribed him a muscle relaxer and sent him home. Later, he sought help from a physical therapist who worked on his neck. When he visited our clinic, we decided to analyze the ligaments. His neutral x-ray showed a dislocated facet that needed to be reset by a neurosurgeon. It turned out that the entire facet capsule had been destroyed. 

When I take a cervical flexion-extension x-ray and see bones slipping, it's clear that the ligament is severely damaged. Whether there's angular instability or translational instability, there's ligament damage that exceeds normal thresholds, which the body won't repair on its own. When a ligament is damaged beyond the body's elastic limits, it loses the ability to return to its original shape. This can result in the development of osteophytes and further degeneration, potentially leading to aberrant motion as the anatomy of the joint changes.  

If a cervical spine injury with ligament damage hasn't been properly analyzed after three to six months of persistent neck pain, diagnosis, and treatment planning will suffer. As practitioners, it's crucial to understand the mechanism of injury. Otherwise, the treatment plan may be incorrect and inadequate due to a lack of accurate diagnosis.  

Ligament damage is often overlooked despite its serious consequences. When ligaments are constantly stressed, they display 'creep behavior' - a time-dependent increase in strain that causes them to stretch out over time, referred to as 'plasticity'. This can result in various symptoms, including disabling pain, vertigo, and tinnitus. 

When a cervical vertebrae's ligament is damaged, and the vertebrae start sliding forward and backward, it can only be detected with flexion/extension radiographic imaging. This imaging will identify two types of instability:  

  1. Angular Instability: joint becomes hypermobile 
  2. Translational Instability: joint slips out of position, or translates to a new position 

The extent of movement helps us understand how much laxity is in the ligament. The bassline limits you need to be aware as outlined in the AMA Guides to the Evaluation of Permanent Impairment 5th edition is 3.5 mm (about 0.14 in) of translation and 11 degrees of angular instability. This is also known as Alteration Of Motion Segment Integrity (AOMSI). 

I had a patient who suffered for two years before having the correct evaluation. When her joints were stabilized via fusion, her pain disappeared. Unfortunately, many people with whiplash injuries don't get checked, and doctors often look for fractures without considering ligament damage. Even a minor car accident can cause long-term pain if the injury is not properly diagnosed and treated. According to Dr. White and Dr. Punjabi's clinical biomechanics research from the 70s, 80s, and 90s, 3.5 millimeters of translation is a definite sign of ligament damage. 

What About Body Types, Age, Sex, and Other Biomechanical Factors: 

On my bucket list, I want to meet Dr. Punjabi. He is an absolute GENIUS. He pioneered a research-focused, unbiased approach, proving the crucial role of spinal biomechanics. He emphasized the importance of neck lordosis, countering popular belief, and presented proof of the relationship between ligament injury, instability, and the relative translation of vertebrae. These principles have been adopted by the AMA guides and are still in use today. Therefore, it's crucial to understand if any angular instability is present when evaluating permanent impairment. 

A common question concerns hypermobility, often seen in individuals with loose ligaments such as young girls. However, the real question is whether the condition is due to ligament damage. One study has noted that hypermobility often lacks symptoms. When patients experience sharp pain when moving their necks, it signifies instability rather than hypermobility. Instances of minor instability may lead to pain and musculoskeletal symptoms, while moderate instability also involves autonomic nervous system symptoms. 

One interesting point of moderate instability is positional radiculopathy, where patients experience numbness in their arms due to nerve compression in the neural canal. The focus often falls on disc injuries, overlooking ligament instability. Positional radiculopathy occurs when the anterior longitudinal ligament is injured and extended beyond its normal range of motion, causing a narrowing of the neurocanal resulting in facet closing, resulting in pinching of the nerve roots. Contrary to common assumption, such symptoms can occur even without disc herniation, which highlights the need to examine the ligaments. Severe instability can lead to significant neurological complications and persistent somatic nerve symptoms, necessitating spinal fusion. A proper evaluation is crucial to reach an accurate diagnosis. 

The human spine has multiple curves acting together like springs to accommodate the weight of the head. The distribution of load between the facet joints and the discs is essential for maintaining the spinal structure. Contemporary postural habits and loss of neck lordosis often result in a load reversal, with 80% on the disc and 20% on the facets, speeding up the degenerative process. This situation, combined with ligament laxity, can lead to faster osteoarthritis development. 

The article written by Danielle Stilen also highlights several disorders, including whiplash trauma, which can be challenging to diagnose and treat due to the discrepancy between the injury's severity and the symptoms' intensity. Such injuries often go unreported, leaving patients without proper treatment. Symptoms may range from neck pain, headaches, dizziness, and vertigo to paresthesia in the upper extremities. 

Vertebral basilar artery insufficiency is another noteworthy disorder, with symptoms similar to concussion. Ligament laxity or cervical instability can lead to artery blockage, going undetected in many cases. This can leave a vast number of patients untreated or improperly diagnosed, thus impacting their long-term care success. 

The article written by Danielle Stilen concludes that the capsular ligaments are the primary stabilizing structures of the facet joints in the cervical spine and are a major source of chronic neck pain. This pain often indicates a state of instability in the cervical spine, commonly associated with conditions such as: 

  • Disc herniation 
  • Cervical spondylosis 
  • Degeneration 
  • Whiplash injury 
  • Post-concussion syndrome 
  • Vertebral basilar insufficiency 
  • Borrelia syndrome 


Recognizing cervical instability as a key component is crucial. Particularly in car accidents, the chance of ligament damage is high due to the mechanism of injury. Understanding the science behind this is vital for improved patient care and accurate diagnosis, leading to more effective treatment protocols. This information is essential for healthcare professionals aiming to provide better patient care and for legal professionals fighting for their clients. 

Make sure to keep an eye on your cases. If they are stalled, the patient has consistent complaints, or there is no imaging, take action! Make sure they get radiographic imaging. That will give you positive findings on your cases.  

Like always, to more evidence-based findings,  

Dr. Brandon Carter 

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