Chemonucleolysis was mainly practiced in the 80s and 90s. The prolapsed disc is dissolved by injecting a lyzing substance, so that it stops compressing nerves. The patients are subjectively relieved and less impaired, but the procedure involves a risk of several complications and is rarely being practiced anymore.
The intervertebral disk is an articular disk between the osseous parts of the spine. It consists of an outer fibrocartilagineous ring and a softer inner nucleus pulposus. On top and bottom, it's protected by a layer of hyaline cartilage. The nucleus can burst through the fibrous ring, which is called a prolapse. Depending on direction and vertebral height of the prolapse, it causes symptoms like pain, loss of reflexes, and pareses.