- Disc extrusion
- Intravertebral disc herniation
- Free fragment
- Sequestered disc
- Herniated nucleus pulposis
potential cause of neck or back pain is a herniated disk, sometimes referred to
a disc protrusion. The spinal column is made up of bones (vertebrae) that are
stacked upon one another and separated by a cushion referred to as an
intervertebral disc. A disc consists of an outer layer of tough supportive
fibers called annular fibers. The annular fibers wrap around a soft gel like
center called the nucleus pulposis. The discs absorb shock and allow for
movement. They also serve as spacers creating height between vertebrae
providing space for spinal nerves to exit on either side of the spine through
openings called neuroforamen.
a disc herniates, disruption of the annulus allows the gel like center to take
the path of least resistance and migrate through the tears. In some cases this
causes the disc to protrude into the spinal canal. With more serious annular disruption
the gel like center of the disc may extend beyond the outer annular fibers.
When this occurs it is called a disc extrusion. If a piece breaks off of the
disc extrusion this is referred to as a sequestered disc fragment. A disc
herniation can directly put pressure on the adjacent spinal cord and/or spinal
nerve. This can cause pain, numbness, tingling or weakness in the back, legs or
arms, depending on the location of the disc herniation.
Classification of Disc
important that physicians of various disciplines agree and understand the use
of common terminology to describe different disease processes. Standardization
of language or terminology is often a challenge. IN 1995 the North American
Spine Society (NASS) initiated efforts to standardize the use of terminology as
it applies to various disorders of the intervertebral disc. They received
assistance from the American Society of Spine Radiology (ASSR) and the American
Society of Neuroradiology (ASNR). The efforts lead to the development of
recommended classifications, definitions and criteria for different disc
disorders at various stages of development. The use of commonly accepted and
understood terminology helps physicians accurately communicate with their
patients and with each other. It influences the type of care recommended to
patients with spine disorders.
following disc disorder classifications and their descriptions are derived form
the nomenclature and classification of lumbar disc pathology, recommendations
of the combined task forces of the North American Spine Society, American
Society of Spine Radiology and American Society of Neuroradiology.