Radiographs are an important method of measuring abnormal motion of the spine. There are many methods to do this as well as techniques. When it comes to injury we may use standard as well as custom techniques to take the images as well as measure any deviations from normal and give values which relate to severity and potential future premature spinal degeneration. Also as notes below we use measurements as listed in the AMA Guide to Permanent Impairment, 5th edition, to determine disability/impairment for legal reasons.
Skeletal Radiol. 1995 May;24(4):263-6. Hyperextension strain or “whiplash” injuries to the cervical spine. Griffiths HJ, Olson PN, Everson LI, Winemiller M. Source Department of Radiology, University of Minnesota Hospital and Clinical, Minneapolis 55455, USA. Abstract PURPOSE: To define “whiplash” radiologically. MATERIAL AND METHODS: A full cervical spine radiographic series (including flexion and extension views) was reviewed in 40 patients with clinically proven “whiplash” injuries and compared to the radiographs in 105 normal controls. The level and degree of kinking or kyphosis, subluxation, and the difference in the amount of fanning between spinous processes on flexion and extension films were measured in each patient. RESULTS: Localized kinking greater than 10 degrees and over 12 mm of fanning, often occurring at the level below the kinking or kyphosis, occurred mainly in the group of whiplash patients (sensitivity 81%, specificity 76%, accuracy 80%). CONCLUSIONS: Localized kinking greater than 10 degrees and fanning greater than 12 mm are useful measurements by which to separate patients with true whiplash injuries from those with minor ligamentous tears. Flexion and extension views are essential to help define whiplash and other ligamentous injuries of the cervical spine.
The American Medical Association (AMA) Guides place a high impairment rating on a loss of motion segment integrity. In the cervical spine, 3.5mm equals 25-28% impairment. This is so important and severe that the Guides equate this damage as equal to a vertebra that has a compression fracture greater than 50%. The reason is that this type of damage to the soft tissue causes abnormal function of the spine and posture. This ligament (soft tissue) instability can lead to a loss of cervical and/or lumbar lordosis. This kyphotic spine is an abnormal form and leads to abnormal function. Abnormal anatomy causes abnormal physiology, which results in pathology. This adverse mechanical tension on the central nervous system can lead to a chronic central mediated pain and syndrome. Current research shows us that the the lordotic curves of the spine give the spine strength and flexibility, therefore, it is concluded that a loss of lordosis increases the risk of injury to the cervical spine following axial loading. Contact us if you want more of the science that further explains the anatomy of ligamentous injury.