Subjects must meet all inclusion and exclusion criteria listed below for participation in the study.

Inclusion Criteria:

• Ages 18-60; male/female.

• Diagnosis of mild to moderate degenerative disc disease (DDD), which requires:

  • back pain of at least 30/100 as measured on a visual analog scale, with or without leg (radicular) pain; and
  • radiographic confirmation of the following, as determined by computed tomography (CT), magnetic resonance imaging (MRI), discography, plain film, myelography and/or flexion/extension films: up to Modic I changes on MRI, with decreased disc height up to 50% of adjacent level, and no significant osteophytes; with or without a contained disc herniation.
• Candidate for either surgery with Wallis or aggressive conservative management.
• Requires treatment at one or two lumbar levels between L1 and L5.
• Experienced symptoms for at least three months without significant resolution.
• Has undergone a regimen of at least four weeks of anti-inflammatory medication for the current episode of back pain and had exposure to physical therapy.
• Minimum baseline Oswestry score of 30% (15/50).
• 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 subject informed consent.

Exclusion Criteria:

• Significant neuroforaminal compression requiring discectomy or foraminotomy
• Radiographic evidence of DDD at L5-S1
• Radiographic confirmation of severe facet joint disease or degeneration.
• History of any lumbar disc treatment intended to remove the disc, e.g. surgery, intradiscal electrothermal therapy (IDET), laser or enzymes such as chymopapain.
• Clinically compromised vertebral bodies at the affected level due to current or past trauma, e.g., sustained pathological fracture or multiple fractures of vertebrae.
• Unwilling to comply with 8 weeks of physical therapy.
• Subject refuses to consider epidural or facet injections for leg or back pain.
• Active systemic infection or infection at the operative site
• Osteoporosis. The Simple Calculated Osteoporosis Risk Estimation (SCORE) questionnaire will be used to screen subjects for osteoporosis; subjects whose screening suggests risk will undergo a dual-energy x-ray absorptiometry (DEXA) scan. Subjects will be excluded if the DEXA scan results indicate a T-score equal to or worse than -2.5, in accordance with the World Health Organization definition of osteoporosis.
• Paget's disease, osteomalacia, or any other metabolic bone disease other than osteoporosis, which is addressed above
• Rheumatoid arthritis, lupus, or other autoimmune disease
• AIDS, HIV, or Hepatitis
• Known allergy to titanium, polyetheretherketone, or polyester
• Current pathological lesions, such as tumor
• Congenital lumbar spinal stenosis
• Clinically relevant instability on flexion-extension as determined by the investigator by overlaying films.
• Cauda equina syndrome
• Pregnant at time of enrollment or with plans to become pregnant within the next three years
• Concomitant conditions requiring steroid treatment or prior steroid usage for more than one of the preceding three months
• Diabetes mellitus requiring daily insulin management
• Extreme obesity, as defined by National Institutes of Health (NIH) Clinical Guidelines (body mass index [BMI] > 35)
• Fusion previously performed at the same or an adjacent level; or other instrumented spinal surgery at the operative level.
• Prior participation in study of any experimental spinal implant or treatment
• Pending litigation against a health care professional
• Life expectancy of less than three years
• History of any invasive malignancy (except for non-melanoma skin cancer), unless treated with curative intent and with no clinical signs or symptoms of the malignancy for at least 5 years
• Current or recent history of substance abuse (alcoholism and/or narcotic addiction) requiring intervention
• Spondylolysis
• Translation greater than 2 mm at the symptomatic level
• Significant scoliosis (Cobb angle > 25 degrees) or scoliosis otherwise requiring surgical correction
• Kyphosis requiring surgical correction