| abstract |
A packaged prosthetic disc nucleus (20) including a prosthetic disc nucleus (22) and a retainer (24). The prosthetic disc nucleus (22) includes a hydrogel core (26) formed to hydrate from a dehydrated state. Further, the prosthetic disc nucleus (22) is configured to such that following implantation into a nucleus cavity, the hydrogel core (26) hydrates to a final hydrated state. The retainer (24) selectively contains the prosthetic disc nucleus (22). Further, upon contact with a hydration liquid, the retainer (24) is configured to allow the hydrogel core (26) to hydrate from the dehydrated state while preventing the hydrogel core (26) from hydrating to the final hydrated state. Thus, the prosthetic disc nucleus (22) is constrained by the retainer (24) in a partially hydrated state. In one preferred embodiment, the combination prosthetic disc nucleus/retainer is sealed within an outer enclosure, such as a pouch, that also contains a hydration liquid for hyrating the hyrogel core. During use, the prosthetic disc nucleus is removed from the retainer and implanted in the partially hydrated state. |