Table 1.

Inclusion/exclusion criteria

Inclusion

Exclusion

Skeletally mature (age, 18 –70) BMI <35 Degenerative Disc Disease at or levels between L3-S1 confirmed by: 1) Self reports of greater amount of back pain compared with leg pain; 2) MRI or discography with concordant pain within 6 months. Self reports preoperative Visual Analog Scale score for back pain ≥40% Self reports preoperative Oswestry Disability Index score 40% Documented symptoms for minimum of months Patient is competent and has signed the informed consent

Symptomatic DDD at more than levels between L3-S1. Patient has experienced previous abdominal surgeries which could compromise surgical exposure. Patient is pregnant or seeking to become pregnant during the study. Previous diagnosed Paget's disease, osteomalacia, other metabolic bone disease or is insulin-dependent. Bone density measurements indicating osteopenia or osteoporosis (DEXA score of −1 or less) Significant facet joint arthritis Active infection Chronic steroid use Known history of metal or plastic allergy Spondylolysis at index level Active malignancy Spinal tumor Previously diagnosed autoimmune disorders or immune compromised Spondylolysthesis ≥ 3mm (Grade 1) Significant instability ≥ 3mm indicated by F/radiograph Lumbar scoliosis > 10% Mid-sagittal stenosis < 11mm (by CT or MRI) Prior fusion adjacent to the index level. Positive single or bilateral straight leg raise test. Previous surgical procedures at the index level that would preclude the placement of the device such as extensive posterior decompression procedures. Current treatment for psychosocial disorders (eg, chemical dependence). Currently smoker. Return visits burdensome to patient. Currently participating in another investigational study that could interfere with the outcome measurements of this study.