Anatomy
The lumbar spine consists of 5 movable vertebrae numbered L1-L5. These vertebrae are designed to be incredibly strong, protecting the sensitive spinal cord, and spinal nerve roots. There are 3 majors parts to the lumbar vertebrae, labeled as the body, spinous processes, and the transverse processes. In between each of the vertebrae are vertebral discs. They consist of a rigged outer structure known as the annulus fibrosis, and a more gelatinous center known as the nucleus pulposus.
Facet Joints
Facet joints link the vertebrae directly above and below to form a working unit that permits movement of the spine. These are directly related to the cause of Spondylolysis, being that the cause is based upon the anterior/posterior translation that occurs at this joint.
Scotty Dog Fracture
The scotty dog sign refers to the normal appearance of the lumbar spine when seen obliquely. On oblique views, the posterior elements form the figure of a Scotty dog with the
- the transverse process being the nose
- the pedicle forming the eye
- the inferior articular facet being the front leg
- the superior articular facet representing the ear
- the pars interarticularis (the portion of the lamina that lies between the facets) equivalent to the neck of the dog.
Spondylolysis
This is considered to be the most common cause of low back pain in adolescent athletes. This injury is a fracture to the pars interarticularis region of the lumbar vertebrae. This fracture most commonly affects the 5th lumbar vertebrae and, much less commonly, the 4th vertebrae.
References on page (In order)
“Spondylolysis and Spondylolisthesis -OrthoInfo - AAOS.” Web. 23 Apr. 2013
“Google Image Result for Http://rollerderbyfitness.files.wordpress.com/2012/05/sq04.jpg.” Web. 23 Apr. 2013.
“Google Image Result for http://s3.amazonaws.com/static.texastribune.org/media/images/Concussion-Practice_jpg_800x1000_q100.jpg.” Web. 23 Apr. 2013.
“Google Image Result for Http://www.athleticadvisor.com/images/plyo_images/squat_jump.jpg.” Web. 23 Apr. 2013.
“Google Image Result for Http://rollerderbyfitness.files.wordpress.com/2012/05/sq04.jpg.” Web. 23 Apr. 2013.
“Google Image Result for http://s3.amazonaws.com/static.texastribune.org/media/images/Concussion-Practice_jpg_800x1000_q100.jpg.” Web. 23 Apr. 2013.
“Google Image Result for Http://www.athleticadvisor.com/images/plyo_images/squat_jump.jpg.” Web. 23 Apr. 2013.