hyperflexion mechanism of cervical SCI: CAUSE
- head on collision in which head strikes steering wheel
- blow to back of the head
- compression anteriorly, distraction posteriorly
- commonly C5-C7
hyper flexion of cervical spine : TISSUES INJURED
wedge fx of vertebral body, tearing of posterior ligaments, anterior dislocation of vertebral body, disruption of disc, fx of post elements(spinous process, laminae, pedicles)
Flexion with rotation mechanism of cervical SCI: CAUSE
- often seen in SB
- results in dislocation and locking of a single facet joint
- often stable situation
Flexion rotation of cervical spine: TISSUES INJURED
- unilateral facet dislocation
- fx of lamina or pedicle
- neurologic:brown squared (injury to one side of the spinal cord in which the spinal cord is damaged but is not severed completely. ), nn roots
vertebral compression of cervical SCI: CAUSE
- high velocity blow to top of head
- have burst fx (comminuted)
- fx fragments may migrate post & enter SC
vertical compression/axial loading cervical spine: TISSUES INJURED
- rupture of disc
- frequently occurs to C4-C5 resulting in complete quadriplegia
hyperextension of cervical spine: CAUSE
• strong post force‐rearend collision,fall and hit chin or
forehead (on tub)
• distraction anteriorly,compression posteriorly
hyperextension of cervical spine: TISSUES INJURED
• fractures of post elements (spinousprocesses, laminae, facets)
• avulsion fractures of anterior aspect of vertebrae
-ant structures torn
-rupture or disruption of disc
-C4-C5 most common location
Flexion distraction of the lumbar (chance fx): CAUSES
- results from use of the lap belt without shoulder restraint
- lap belt becomes a pivot point (fulcrum)
- flexion-distraction force from that point
flexion distraction of the lumbar spine: TISSUES INJURED
- bony fx and ligamentous tears are horizontally oriented
- injury in thoracic-lumbar area
- may also have sever internal injuries
Penetrating Wound of Lumbar spine: CAUSES
- ->low velocity: knife, ice pick, low velocity bullets
- ->high velocity: high powered rifles, explosion-does not have to penetrate spine or spinal cord to cause damage to neural tissues-concussive force
Diagnosing SCI
- C-spine-lateral radiograph (85% accuracy)
- CT
- Myelography (used in conjunction with CT)
- MRI
Pathophysiology of SCI
- physical alteration of the cord/cutting of the cord fibers
- cord intact with auto destructive process (gunshot wound)
- Cord intact with vascular compromise
Non-Traumatic SCI etiologies
- vascular malformations (aneurism, thrombus,embolus,hemorrhage)
- vertebral degeneration/subluxation
- primary or secondary neoplasms
- infections
- abscess (necrosis of SC tissue)
- congenital defect (spina bifida)
Traumatic SCI etiologies
MVA cause 46 % of all SCI
80% of individuals with SCI are males w/ 1/2 between age of 15 & 30 and 11.5 % in over 60y/o
factors affecting vertebral injury
- direction of force
- position of persons head at the time
- magnitude, rate of application and duration of injuring force
- point of application
Cervical Spine injuries
- poor stability (designed for mobility)
- 40% incidence in cord injury with damage to cervical vertebrae
- 52% of SCI occur in cervical region
3 most common damaging forces to the cervical spine
- flexion
- vertical loading
- extension
SCI to thoracic spine
typically caused by GSW, MVA, Falls
- T12-L1 junction is most common injured
- **not typically injured by isolated extension or lateral flexion forces
SCI of thoracic spine: Flexion
wedge fractures-most common
-post ligamentous complex damaged d/t distractive forces (severe)
SCI of thoracic spine: Vertical Compression
burst fx, bone fragments into spinal cord
flexion-rotation of lumbar spine : CAUSES
-post to ant directed force at rotated vertebral column
flexion-rotation of lumbar spine : Tissues Injured
- fx dislocation
- post ligamentous complex ruptured and accompanied by the vertebral body fx
- ->highly unstable injury
Functional classification of SCI
quadriplegia-cervical injury, visceral involvement paresis=incomplete, plegia-complete
paraplegia-LE trunk involvement, visceral involvement
