Approximately 79,000 spinal fractures occur annually in the United States. Roughly three out of every four fractures involve either the thoracic or the lumbar spine1,2. The most common site of injury in the thoracic and lumbar spine is the thoracolumbar junction, the mechanical transition zone between the relatively rigid thoracic spine and the more flexible lumbar region35. The thoracolumbar junction receives 35 to 45% of the torsional and shear forces on the spine. This flexibility, combined with the curvature arising from biomechanical adaption to upright posture, makes the thoracolumbar junction more prone to injury than the lumbar spine 6.
"Thoracolumbar and Lumbar Burst Fractures,"
4, Article 3.
Available at: http://jdc.jefferson.edu/jhnj/vol4/iss4/3