- See:
-
Flexion and Extension Views
-
SCIWORA Syndrome:
- Anterior Ligamentous Disruption:
- detected by presence of small anteroinferior avulsions and segmental
disc widening;
- ligaments include: anterior longitudinal ligament &
Annulus fibrosus;
- w/ complete cervical dislocation from anterior ligament failure, more
stable internal fixation (posterior plate stabilization) should be
considered to permit early patient mobilization;
- note: failure of the anterior vertebral body should always suggest
posterior ligament failure;
- if posterior ligament failure is ruled out, then treat patient w/ hard collar;
- w/ post. lig. disruption (or with middle column collapse)
- treat w/ gradual traction, reduction, & posterior stabilization
and then fusion;
- Middle Column Ligamentous Disruption:
- note: that the
Middle column ligaments are also critical for stability
against distractive forces; (post. long. lig. &
annulus fibrosis)
- sectioning of middle
ligamentous complex (posterior longitudinal
ligament and annulus) creates segment angulation of 11 deg and
translation of 3.5 mm;
- hence, evidence of middle
ligamentous complex disrupton
- interspinous or intervertebral angulation 11 deg greater
than the adjacent spinal segment (normally 2-4 deg)
- horizontal translation greater than 3.5 mm;
- intervetebral disk space separation > 1.7 mm;
- Posterior Ligamentous Disruption:
- failure of posterior
ligamentous complex may occur in conjunction w/
middle complex disruption or with other instability patterns;
- radiographic signs of posterior ligamentous disruption include
dislocation or subluxation of facets,
Facet Joint widening, &
malalignment of the spinous processes on the
AP view;
- if vertebral body translation of > 3.5 mm occurs in conjuction w/
facet dislocation, then middle
ligament complex is disrupted as well;
- this is a highly unstable injury w/ neurologic deficits
- decompression of vertebral fragments may be necessary
- reconstruction of the spinal segment with neural decompression
then requires strut graft placement & either prolonged
halo
immobilization or internal fixation thru a posterior approach;
- anterior plating alone may not be rigid enough to restore
stability to the spine;
- disruption of posterior
ligamentous complex in face of anaterior frx
or dislocation is a strong indication of instability and of
potential necessity for surgical stabilization;
- exceptions may include the upper thoracic spine, which is inherently
more stable, and with bony
Chance Fracture;
-
compression frx of 3 sequential vertebrae leads to increase
in risk of
posttraumatic kyphosis;
- Flexion Instability:
- there are two types of flexion instability patterns in which posterior
and middle ligamentous complexes are ruptured but the anterior
complex is intact;
- in one of these patterns there may be posterior element widening w/
subtle
compression frx of vertebral body;
- other pattern is
bilateral facet dislocation;
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Hyperextension-dislocation of the cervical spine. Ligament injuries
demonstrated by magnetic resonance imaging.
