The annulus is the area of the intervertebral disc that connects each vertebra together. With age, the disc begins to degenerate and can sometimes tear with repetitive motions. An annular tear may also occur after a traumatic injury, common in athletes that play high-impact sports or people with very physical occupations.
An annular tear is categorized by the nature of the tear and the layers of the annulus it affects. The different types of annular tear include:
- Radial tears — Typically caused by the natural aging process, radial tears begin at the center of the disc and extend all the way through the outer layer of the annulus fibrosus. These tears can cause a disc to herniate, which occurs when the center nucleus of a disc extrudes through the tear to the outside of the disc.
- Peripheral tears — These tears occur in the outer fibers of the annulus fibrosus and are usually brought on by traumatic injury or contact with a bone spur. Peripheral tears can lead to the degeneration or breakdown of an intervertebral disc.
- Concentric tears — When a tear occurs between the layers of the annulus fibrosus circumferentially, it is called a concentric tear, which is usually caused by injury.