An intervertebral disc nucleus replacement is provided that is configurable into a first configuration to be assumed while the replacement is implanted in the nuclear cavity and a second configuration to be assumed during the procedure of inserting the replacement into the nuclear cavity. The first configuration may have an accordion-like structure formed by a plurality of sections folded in an alternating, zigzag-like manner, and may be sized and shaped to conform to the nuclear cavity. The second configuration may be formed by straightening the plurality of folded sections into an unfolded, elongated, linear member, thereby affording a smaller effective cross-section. The nucleus replacement may be made of an elastic material having shape memory and may be formed so that the first configuration is an unmanipulated or relaxed configuration and the second configuration is a manipulated or unrelaxed configuration.