Each intervertebral disc has two main parts:
- A soft, gel-like center called the nucleus pulposus
- A stronger outer ring called the annulus fibrosus
Healthy discs help distribute pressure across the spine and allow for spine movement.
Please review the Lumbosacral spine anatomy section to learn more about the healthy spine.
As a disc ages or becomes injured, its structure may change. Below are some of the ways this can happen.
Major Diagnosis Types
Below are the major types we see in our clinic. Click on available links to learn about our approach to the problems.
Degenerative Disc Disease
Degenerative disc disease occurs when a disc gradually loses water, flexibility, and height. Although the word “disease” is used, this is usually an age-related wear process rather than an illness.
Disc degeneration may increase stress on the nearby vertebrae, facet joints, and nerves.
Disc Herniation
A lumbar disc herniation occurs when material from inside the disc pushes through a weakened or torn area in the outer disc.
The herniated material may irritate or compress a nearby nerve, causing pain that travels into the buttock or leg.
Vertebrogenic Pain
Vertebrogenic pain is chronic low back pain believed to come from damaged vertebral endplates next to a degenerating disc.
Pain signals may travel through a small nerve inside the vertebral body called the basivertebral nerve.
Minor Diagnosis Types
These terms are often encountered, but are either less often treated or described within one of the above diagnoses.
Annular Tear
An annular tear is a split or crack in the outer ring of the disc.
Some annular tears cause no symptoms. Others may produce localized back pain or allow the inner disc material to move outward and form a herniation.
Disc Bulge
A disc bulge occurs when a broad portion of the disc extends beyond its normal boundary.
Disc bulges are common and do not always cause symptoms. A bulging disc may become painful when it narrows the spinal canal or presses against a nerve.
Disc Height Loss
A degenerating disc may become thinner and lose height.
Disc height loss may narrow the openings through which the spinal nerves exit. It can also place additional stress on the facet joints and contribute to abnormal movement between the vertebrae.