Replacement of the degenerative nucleus pulposus, the shock absorbing tissue in spine, serves as the next frontier in the surgical management of intervertebral disc problems. Previous techniques used for this problem include the fusion of the anterior and posterior vertebra with bone graphs or metal and total disc replacement, both of which are extremely invasive and leave considerable amounts of scar tissue. The current study evaluated the biomechanical properties of the in situ curable polyurethane nucleus pulposus replacement, the NuDisc. Based on the biomechanical analysis conducted in the study, it can be concluded that the multidirectional flexibility properties remain unchanged from the intact condition following reconstruction, and are maintained following a 40,000 cycle fatigue loading parameter (p=0.91). The study provides a biomechanical basis for the use of this device and serves to augment ongoing clinical investigations.