By Marie Dauenheimer and Joan Tycko, Board Certified Medical Illustrators
In a past posting we discussed the normal anatomy of the vertebral column. To review, the human vertebral column acts as the main support for the body, protects the spinal cord and allows for movements such as rotation, bending and twisting. The spine’s multiple roles, and its complex design, make it a marvel of engineering and vulnerable to injury.
Illustration: Lateral view of the normal vertebral column
Degenerative disk disease is part of the normal aging process. Over time changes can be seen in the vertebral bodies as they compress, and osteophytes and abnormal bone growth forms. Changes in the disk itself include flattening, loss of flexibility and formation of fibrocartilage in the nucleus pulposus (the jelly-like substance in the center of the disk).
Illustration: Lateral view showing normal vertebrae and DDD
Pain associated with degenerative disk disease originates from inflammation or compression of the spinal cord and/or spinal nerves. As seen in the illustration of a central stenosis osteophytes narrow the vertebral canal and compress the spinal cord causing pain and loss of function. In a lateral stenosis osteophytes compress the spinal nerves as they exit through the intervertebral foramen.
Illustration: Superior view of a vertebrae showing normal anatomy, central stenosis and lateral stenosis
The most mobile portions of the vertebral column are found in the cervical and lumbar sections and these areas are frequently the most vulnerable to injury. A bulging disk is commonly seen in the aging process and might not causes symptoms. However, a herniated disk is more serious. In herniations the nucleus pulposus pushes out of the stronger fibrous annulus, and compresses the spinal cord and/or spinal nerves. This type of injury is often associated with loss of function in the limbs.
llustration: Superior view of a herniated disk showing nucleus pulposus compressing the spinal cord and spinal nerve
Surgical interventions include laminectomy, diskectomy and spinal fusion.
Originally published by the Trial Lawyers Association of Metropolitan Washington, DC in their Summer 2014 newsletter. All illustrations and written content copyrighted by Compel Visuals LLC.