Efficacy of the Aspen Spinous Process System in Anterior Lumbar Interbody Fusion (ALIF)

This is a multi-center, prospective randomized clinical study to evaluate the clinical outcome of subjects with DDD who are treated with ALIF and supplemental posterior fixation using Aspen compared to pedicle screw instrumentation. The study will involve up to approximately 25 investigational sites and enroll up to 156 67 subjects. The randomization ratio of two Aspen subjects to one pedicle screw subject (2:1) will be utilized. Subjects with lumbar DDD who are candidates for ALIF at a single level will be screened for inclusion in the study. If the subject meets all of the eligibility criteria, they will be enrolled and randomized to either the Aspen or pedicle screw group. Subjects will continue to be followed by the guidelines set forth in this clinical protocol, which include: a postoperative discharge exam; six week, three month, six month, and one year post-op visits; and, concludes with a two year post-op visit. The follow-up is counted from the day of surgery. The enrollment period is expected to be approximately 12 months and subjects will be followed for 2 years post-op for the duration of the clinical investigation. The anticipated duration of the study is approximated to be 3 years.