Wallis Stabilization System for Low Back Pain

Inclusion Criteria: * Age 18-60 (inclusive) and skeletally mature. * Diagnosis of mild to moderate DDD at L4-L5 as confirmed by radiography. * Minimum of six months of failed conservative treatment. * Pre-operative visual analog (VAS) low back pain score ≥ 40, on a scale of 100mm, with low back pain greater than left or right leg pain. * Preoperative baseline Oswestry Disability Index (ODI) score of ≥ 40 on a 100 point scale. * Physically and mentally able to comply with the protocol, including ability to read and complete required forms, and willing and able to adhere to the follow-up requirements of the protocol. * Voluntarily signs the patient informed consent form. * Patient is a surgical candidate for an anterior approach to the lumbar spine (\< 3 abdominal surgeries). Exclusion Criteria: * The investigator believes that the L1-L2, L2-L3, L3-L4, or L5-S1 level is symptomatic based upon objective evidence, e.g., radiograph, MRI, or discography. * Evidence of a prior fracture or trauma to the vertebral bodies at the affected level and/or the spinous processes at the L4-L5 or adjacent levels. * Osteoporosis or osteopenia or metabolic bone disease as confirmed by DEXA scan (T score \< -1.0). Female subjects older than 45 years of age (or post-menopausal women, history of oophorectomy, or family history of osteoporosis) and male subjects older than 55 years will undergo a pre-operative, dual energy x-ray absorptiometry (DEXA) of the lumbar spine. The DEXA will be used to identify subjects with an indication of osteoporosis, osteopenia or metabolic bone disease. Subjects with a T-score of less than -1.0 will be excluded from the study. * Congenital lumbar spinal stenosis. * Bony lumbar stenosis. * Extreme obesity, as defined by National Institutes of Health (NIH) Clinical Guidelines Body Mass Index (BMI \> 40kg/m2). * A history of any surgical procedure intended to remove or alter the disc (e.g. discectomy, intradiscal electrothermal therapy (IDET) or enzymes), decompress (laminectomy) or fuse, either the index or adjacent levels. * Prior participation in study of any investigational spinal implant or investigational spinal treatment.