- Discussion:
- 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
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.