Cervical Disc Disease encountered in physiatric practice include herniated nucleus pulposus (HNP), degenerative disc disease (DDD), and internal disc disruption (IDD). HNP implies extension of disc material beyond the posterior margin of the vertebral body. Most of the herniation is made up of the annulus fibrosus. DDD involves degenerative annular tears, loss of disc height, and nuclear degradation. IDD describes annular fissuring of the disc without external disc deformation. Cervical radiculopathy (disease of the spinal nerve roots) can result from nerve root injury in the presence of disc herniation or stenosis (narrowing of the spinal canal), most commonly foraminal (openings in the vertebrae for the nerve bundles to enter) stenosis, leading to sensory, motor, or reflex abnormalities in the affected nerve root distribution.
Understanding cervical disc disease requires basic knowledge of anatomy and biomechanics. The intervertebral disc absorbs shock, accommodates movement, provides support, and separates vertebral bodies to lend height to intervertebral foramina. No disc exists between C1 and C2, and only ligaments and joint capsules resist excessive motion. Disc degeneration and/or herniation can injure the spinal cord or nerve roots and result in stenosis and/or myofascial pain.