A nucleus prosthesis is disclosed having a plurality of linked segments configuredto form, in a closed position, a disc shape. A method includes inserting a pluralityof linked segments into an annulus fibrosus and closing the prosthesis so thata first segment inserted into the annulus fibrosus and a last segment insertedinto the annulus fibrosus are substantially abutted. Another method includesinserting a plurality of linked segments into an intervertebral disc space andclosing the prosthesis so that a first segment inserted into the intervertebraldisc space and a last segment inserted into the intervertebral disc space aresubstantially abutted.
