Replacement or supplementation of a nucleus pulposus using a hydrogel

摘要

A nucleus pulposus of an intervertebral disc is supplemented or replaced by an elongated, physiologically fully hydrated hydrogel prosthesis inserted into the central region of an intervertebral disc, where it can fold upon itself to form a prosthesis body within the central region of the annulus fibrosus. The hydrogel prosthesis may have expanded portions that assist in preventing expulsion of the prosthesis through the insertion aperture. An instrument for inserting the prosthesis has a cutter for severing the elongated prosthesis within the central region of the intervertebral disc after a sufficient amount has been implanted.