- includes lamina, pedicles, spinous processes, including supraspinous and intraspinous ligaments, ligamentum flavum, & facet capsules;
- Clay Shoveler's fx
- Ligamentous Instability:
- consists of combined role of right & left Facet Joint & lateral masses in resisting compression;
- ligamentous complex in posterior motion segment resists distraction predominately thru the Facet Joint capsules, and to lesser extent
thru interspinous ligaments; (ligaments include: Facet Joint capsules & interspinous ligaments)
- usually only one facet complex suffers from compressive failure;
- loss of compressive stability occurs when either the inferior or superior articular process is fractured;
- whole lateral mass can be destabilized if the atatched pedicle and lamina are fractured;
- w/ disruption may see Facet Joint widening, & malalignment of facet joints on AP views.
- if vertebral body translation of > 3.5 mm occurs in conjuction w/ facet dislocation, then middle ligamentous complex is disrupted as well;
- another fx thru the posterior elements is the "sentinel fx"
- this is characterized by fractures thru the lamina on either side of the spinous process;
-significance of the sentinel fx is that the loose posterior element may impinge on the Spinal Cord;
- otherwise there is no assoc injury and is considered stable;
- disruption of the posterior ligamentous complex in the face of anaterior fracture 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
The three column spine and its significance in the classification of acute thoracolumbar spinal injuries.
Spinal instability as defined by the three-column spine concept in acute spinal trauma.
Complications in three-column cervical spine injuries requiring anterior-posterior stabilization.