Trauma to the upper thoracic spine: anatomy, biomechanics, and unique imaging features.

This review summarizes the anatomic and biomechanical features of the thoracic spine, which are different from those of the more mobile segments of the spine, and emphasizes their role in trauma. The distinguishing characteristics of the thoracic spine are the presence of the ribs and their articulations. The rib cage restricts motion and adds stiffness to the spine. During trauma, it provides the thoracic spine with additional strength and energy-absorbing capacity. Above the T10 level, most injuries produce a basic pattern consisting of an anterior fracture-dislocation involving two contiguous vertebrae, often with associated neurologic impairment. The definition of spinal instability remains controversial. CT is the imaging technique of choice for evaluation of spine fractures; however, MR imaging is superior in the evaluation of spinal cord injury and posttraumatic disk herniation. MR imaging also provides prognostic information not obtainable with other imaging methods.