The NuBac device is indicated for reconstruction following nucleotomy in skeletally mature patients at least 18 years of age with symptomatic single level degenerative disc disease (DDD) at L4/L5 only.

DDD is defined as discogenic back pain with or without leg pain; with degeneration of the disc as confirmed by patient history, physical examination, radiographic studies showing: decreased disc height, contained herniated nucleus, vacuum phenomenon (dark disc) OR positive discography at the affected level.

These DDD patients should have no more than Grade 1 spondylolisthesis at the involved level and should have failed at least six months of conservative, non-operative care.

Demonstrate non-inferiority compared to ProDisc.

STUDY DESIGN:

Multicenter, prospective, randomized (1:1), controlled study comparing the artificial nucleus to ProDisc. After implanting artificial nucleus in two patients during the training session, enrollment of randomized patients shall begin. The study is expected to be completed in four years.

NUMBER OF INVESTIGATIONAL SITES and INVESTIGATORS:

10 - 20 investigational sites, 1 to 2 investigators per site, approximately 20-40 patients per site

Inclusion Criteria:

• is at least 18 years of age and skeletally mature
• must have symptomatic single level degenerative disc disease at L4/5 requiring surgical treatment
• must have completed a minimum of six months of unsuccessful conservative, non-operative care
• must have discogenic back pain with or without leg pain
• must show radiographic confirmation using plain films, MRI, CT, myelogram or discography of one of the following: decreased disc height when compared to the adjacent level, contained herniated nucleus, or vacuum phenomenon (dark disc)
• must score at least 40% on the Oswestry Disability Index
• must score at least 4 on a 10cm Visual Analog Scale for back pain
• is able to comply with the protocol's follow-up schedule
• must understand and sign the informed consent document

Exclusion Criteria:

• symptomatic DDD at more than one level
• previous fusion at any lumbar level or laminectomy at the target level (discectomy, Intradiscal Electrothermal Annuloplasty, laminotomy, or nucleolysis performed > 6 months ago are permitted)
• clinically compromised vertebral bodies, at the affected level due to previous trauma, i.e., compression or burst fracture
• pars defect
• involved vertebral endplate dimensionally smaller than 34.5 mm in the medial-lateral direction and/or 27 mm in the anterior-posterior direction
• disc height less than 5 mm at the target level
• bony stenosis
• lytic spondylolisthesis, spondylolisthesis greater than 3mm
• lumbar scoliosis greater than 11 degrees.
• osteoporosis, osteopenia, osteomalacia, Paget's disease or metabolic bone disease
• Schmorl's nodes, an incomplete annulus, or endplates that are not intact
• spinal tumors
• symptomatic facet joint disease
• free fragment herniation confirmed radiographically
• isolated radicular compression syndrome, especially due to a disc herniation
• arachnoiditis
• active infection or surgical site infection
• is using any medication known to interfere with bone/soft tissue healing
• rheumatoid arthritis or other autoimmune disease
• systemic disease such as AIDS, HIV, hepatitis
• morbid obesity defined as body mass index (BMI) >40 or a weight more than 100 lbs over ideal body weight
• psychosocial disorders that would preclude accurate evaluation or has a history of substance abuse
• active malignancy except non-melanoma skin cancer; history of any invasive malignancy unless treated and in remission for at least five years
• documented allergies to metal or plastic; i.e., cobalt, chromium, molybdenum, polyethylene, titanium or polyetheretherketone
• pregnancy, or interested in becoming pregnant within the next two years
• prisoner
• involvement in an investigational drug or device study within 30 days

Research parties agree not to make any publications of results until notified in writing by Sponsor that study is complete and results published in peer-reviewed journal; however if not published within 18 months, Research parties may pursue publication of individual results. Research parties must submit communication to Sponsor for review/approval at least 30 days prior to submission. Sponsor can require the modification of the manuscript or delay of publication.