Mechanism of Injury, Trauma, Subluxation and Instability Outline

Transcription

1 Spinal Trauma Instructor: Dr. Jeffrey A. Cronk, DC, CICE Director of Education, Spinal Kinetics. CICE, American Board of Independent Medical Examiners. Mechanism of Injury is just something that you must understand as it can seriously reduce the stress of the medical legal side of a injury practice as well as seriously improve your understanding of what you do as a Chiropractor It is a basic building block in all of spinal misalignment understanding regardless of the profession How a Spinal Subluxation Occurs: Panjabi s model of joint dysfunction. Disturbed kinematics, loss of spatial and temporal integrity of received receptor signals leads to corrupted motor programs. Trauma or cumulative micro-trauma causes sub-failure injury to passive restraints including ligaments, joint capsules, and disks. Pages: 1 of 5

2 A Working Dynamic Model of Subluxation: Trauma/ micro-trauma causes sub-failure to ligaments, joint capsules, and disks. This causes damage to collagen fibers and mechanoreceptors. The result is partial deafferentation, disturbed kinesthesia, and loss of spatial and temporal integrity. The neuromuscular control unit has difficulty interpreting the corrupted mechanoreceptor signals. The muscle response pattern is corrupted, disturbing co-activation, recruitment of spinal muscles, range of motion, and kinematics. Disturbed motor control results in abnormal loads, stresses, and strains leading to further sub-failure injury. Sub-failure injury produces inflammation and causes chronic pain, recurrences, and reduced functional capacity. Spinal Ligaments: Excluding the upper cervical spine, a FSU is connected by 10 ligaments, which serve to protect neural structures by restricting the motion of each FSU (Figure 4). The ligaments also absorb energy during high speed and potentially injurious motions. Trauma to a spinal ligament is called a spinal sprain. Pages: 2 of 5

3 The Spinal Sprain Policy Statement of the International Chiropractic Association: Inherent in most spinal sprain and strain injuries, there exists a biomechanical, neurological component of articular malposition referred to Chiropractically as subluxation. Such subluxation, if not addressed and merely treated with soft tissue therapeutics and/or joint immobilization forms of care, may lead to joint fixation and/or instability and loss of motor unit integrity. It is the opinion of the International Chiropractors Association that in such injuries evidence of the chiropractic vertebral subluxation complex should be analyzed and, if present, be corrected by specific chiropractic articular adjustment before immobilization procedures are applied. Lack of such correction of articular misalignment (subluxation) may result in permanent impairment, for waiting more than an hour, much less days, may lead to joint fixation, motion impairment, neurological insult and/or hypermobility of the intervertebral motor unit. Adjustive reduction of the articular subluxation must be accomplished with due regard to soft tissue injury, attempt to enhance recovery and contribute to the prevention of future joint motion impairment, neurological impairment and deteriorative pathological consequences. Whiplash injury: It has been firmly established for nearly two decades that the primary whiplash injury is an inertial injury to the soft tissues (ligaments and muscles) of the facet joints and disc joint of the neck. (Pain, 1993) Pages: 3 of 5

4 Ligamentous laxity, ligamentous subfailure, ligamentous instability is considered by consensus when you have at least a 1mm offset or more in the neutral (Georges Line), flexion or extension films. It is also considered if there is 7 or more of angular finding on flexion film. Alteration of Motion Segment Integrity is when the laxity measurements---- exceed the measured thresholds as listed in the AMA Guides Spinal Instability is established when we take the ligamentous instability or the AOMSI findings and correlate the patient motor, sensory or pain findings to that/those level(s). Motion of individual spine segments cannot be determined by physical examination but is evaluated with flexion extension roentgenograms pg. 379 AMA Guides When routine x-rays are normal and severe trauma is absent, motion segment alteration is rare; thus, flexion and extension x-rays are indicated only when the physician suspects motion segment alteration from history or findings on routine x-rays. pg. 379 AMA Guides Mechanism of Injury: the source of forces that produce mechanical deformations and physiologic responses that cause an anatomic lesion and functional change in humans Mechanism of Injury is the force that causes a physical deformation and associated non-optimal physical functioning. Pages: 4 of 5

5 Each Mechanism of injury leaves behind a clinical footprint a physical deformation pattern is consistent with the force (mechanism). Each mechanism of injury is a force that deforms tissue and leaves a physiological effect behind. Physicians must assess the deformation pattern, document that the force that caused the injury, as well as identifying its location and severity of the injury. The mechanism of injury tells us little; it is the examination of the deformation patterns left behind that tells us everything. Acceleration Deceleration Spinal Shearing Injury: The auto accident Shear Force --the deformation of a material substance in which parallel internal surfaces slide past one another. Most Events the Overwhelm the Spine Ability to Resist Injury Contain BOTH Compressive Forces and Shearing Forces. These overwhelming forces result in Inter-segmental Spinal Misalignments which can cause global misalignment patterns to occur. Pages: 5 of 5