Patent ID: 8114160

Claim:
An implant device for replacing a nucleus of a natural intervertebral disc, the implant device comprising: a nuclear implant for being inserted through an opening in an annular wall of the natural intervertebral disc and into a nuclear space; upper and lower shells of the implant each comprising a body having a width thereacross; inner facing surfaces of the upper and lower shells each comprising bearing surface portions that engage with one another to provide a bearing interface between the shells such that the upper and lower shells are allowed to articulate with respect to one another; an elongate through hole formed in one of the shells extending across the width thereof; and a pair of blocking members each having a fixed portion that is connected at a respective side of the one shell body via an elongate pin disposed in the elongate through hole such that the blocking members are disposed on either end of the elongate pin and are spaced from each other at a predetermined distance across the one shell body corresponding to the width of the shell body with the pair of blocking members being shiftable between first and second orientations thereof for passing through the annular wall opening so that the implant has a compact configuration sized to fit through the annular wall opening with the blocking members shifted to the first orientation from the second orientation thereof, and an expanded configuration sized such that the implant is kept from being expelled from the nuclear space through the annular wall opening after insertion of the implant by interference between the blocking members shifted from the first orientation to the second orientation thereof and the annular wall.