Safety and Effectiveness Study of Prodisc to Spinal Fusion Surgery

A Multi-Center, Prospective, Randomized, Controlled Clinical Trial Comparing the Safety and Effectiveness of ProDisc to Spinal Fusion Surgery in the Treatment of Discogenic Pain Associated With DDD in the Lumbosacral Spine

The objective of this clinical investigation is to compare the safety and effectiveness of ProDisc total disc replacement to spinal fusion surgery in the treatment of discogenic pain associated with DDD in the lumbosacral spine. There will be separate study arms for one and two level cases.

Inclusion Criteria:

• Degenerative Disc Disease (DDD) in one or two adjacent vertebral levels between L3 and S1. Diagnosis of DDD requires: a)Back and/or leg (radicular) pain; and b)Radiographic confirmation of any 1 of the following by CT, MRI, discography, plain film, myelography and/or flexion/extension films: Instability (greater than or equal to 3mm translation or 5° angulation); Decreased disc height >2mm; Scarring/thickening of annulus fibrosis; Herniated nucleus pulposus; or Vacuum phenomenon.
• Age between 18 and 60 years.
• Failed at least 6 months of conservative treatment.
• Oswestry Low Back Pain Disability Questionnaire score of at least 20/50 (40%)(Interpreted as moderate/severe disability).
• Psychosocially, mentally and physically able to fully comply with this protocol including adhering to follow-up schedule and requirements and filling out forms.
• Signed informed consent.

Exclusion Criteria:

• No more than 2 vertebral levels may have DDD and all diseased levels, either one or two, must be treated.
• Patients with involved vertebral endplates dimensionally smaller than 34.5mm in the medial-lateral and/or 27mm in the anterior-posterior directions.
• Known allergy to titanium, polyethylene, cobalt, chromium, or molybdenum.
• Prior fusion surgery at any vertebral level.
• Clinically compromised vertebral bodies at the affected level(s) due to current or past trauma.
• Radiographic confirmation of facet joint disease or degeneration.
• Lytic spondylolisthesis or spinal stenosis.
• Degenerative spondylolisthesis of grade >1.
• Back or leg pain of unknown etiology.
• Osteopenia or Osteoporosis: A screening questionnaire for osteoporosis, SCORE (Simple Calculated Osteoporosis Risk Estimation), will be used to screen patients to determine if a DEXA scan is required. If DEXA is required, exclusion will be defined as a DEXA bone density measured T score less than
• 1.0. The World Health Organization defines osteoporosis as a DEXA T score less than or equal to -2.5.
• Paget's disease, osteomalacia or any other metabolic bone disease (excluding osteoporosis which is addressed above).
• Morbid obesity defined as a body mass index >40 or a weight more than 100 lbs. over ideal body weight.
• Pregnant or interested in becoming pregnant in the next 3 years.
• Active infection - systemic or local.
• Taking medication or any drug known to potentially interfere with bone/soft tissue healing (e.g., steroids).
• Rheumatoid arthritis or other autoimmune disease.
• Systemic disease including AIDS, HIV, Hepatitis.
• Active malignancy: A patient with a history of any invasive malignancy (except non-melanoma skin cancer), unless he/she has been treated with curative intent and there has been no clinical signs or symptoms of the malignancy for at least 5 years.