The disc is a firm spongy material located between the vertebral bones of the spine. Severe damage to the disc may require disc removal or discectomy.

The disc protects the spine from compressive forces and excess motion. Doctors try to leave as much of the disc as possible. A limited discectomy removes part, but not all, of the disc. This may be up to half of the inner portion of the disc called the nucleus pulposus.

A radical discectomy takes out the entire center of the disc. The outer part of the disc is called the annulus. Removing part or all of the annulus is an annulotomy.