A degenerated nucleus pulposus located in a central core (110) region of an intervertebral disc (106) within the annulus fibrosus (108) is supplemented or replaced by a method wherein an amount of a biocompatible material is introduced into the central core region by a process including the steps of 1) forming a channel (116) through a vertebral body (102) adjacent to said intervertebral disc, extending from an exterior surface of the vertebral body to the central core region of the annulus fibrosus; 2) introducing an amount of a biocompatible material through the channel into the central core region of the annulus fibrosus; 3) pressurizing the biocompatible material through the channel to a postsurgical pressure sufficient to alleviate symptoms caused by the degenerated nucleus pulposus; and 4) sealing the channel while maintaining the sufficient postsurgical pressure.