Safety and Effectiveness Study of Prodisc to Spinal Fusion Surgery

Study Overview
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Brief Summary
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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.

Official Title
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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

Conditions
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Spinal Diseases

Intervention / Treatment
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* Device: ProDisc
* Procedure: Spinal Fusion


Participation Criteria
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Eligibility Criteria
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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.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: 1-Level Fusion<br>Spinal fusion at a single lumbar level. | Procedure: Spinal Fusion<br>* A circumferential fusion will be utilized as the control group in this study. The technique will consist of an interbody fusion procedure using commercially available femoral ring allograft. A posterior lateral fusion with autogenous iliac crest bone graft, combined with pedicle screw instrumentation.<br>|
| Experimental: 1-Level ProDisc<br>Total disc replacement with the ProDisc device at one spinal lumbar level. | Device: ProDisc<br>* Total disc replacement with ProDisc<br>|
| Active Comparator: 2-Level Fusion<br>Spinal fusion at two adjacent lumbar levels. | Procedure: Spinal Fusion<br>* A circumferential fusion will be utilized as the control group in this study. The technique will consist of an interbody fusion procedure using commercially available femoral ring allograft. A posterior lateral fusion with autogenous iliac crest bone graft, combined with pedicle screw instrumentation.<br>|
| Experimental: 2-Level ProDisc<br>Total disc replacement with the ProDisc device at two adjacent lumbar levels. | Device: ProDisc<br>* Total disc replacement with ProDisc<br>|
| Experimental: 1-level ProDisc (non-randomized)<br>Total disc replacement with the ProDisc device for non-randomized subjects at one spinal lumbar level. | Device: ProDisc<br>* Total disc replacement with ProDisc<br>|
| Active Comparator: 2-Level ProDisc (Continued Access)<br>Total disc replacement with the ProDisc device for non-randomized subjects at two spinal lumbar levels (only followed out to 24 months) | Device: ProDisc<br>* Total disc replacement with ProDisc<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Overall Success | Overall success was a composite endpoint. A ProDisc patient was considered an overall success if, and only if, ALL of the following criteria were met: ODI score improved by at least 15% from baseline; SF-36 score improved from baseline; Neurologic parameters maintained or improved from baseline; No re-operations to modify or remove the implant; and Independent radiographic review confirmed no migration/subsidence, radiolucency, loss of disc height, loss of range of motion, or boney fusion. A Fusion patient was a considered to be a success if, and only if, ALL of the following criteria were met: Same as above Same as above Same as above No re-operations to modify the fusion site or correct a complication with an implant; and Independent radiographic review confirmed strong evidence of fusion and no motion, visible gaps in fusion mass, loss of disc height, migration/subsidence, implant loosening, halos, or radiolucencies | 24 Months | 
| Overall Success | Overall success was a composite endpoint. A ProDisc patient was considered an overall success if, and only if, ALL of the following criteria were met: ODI score improved by at least 15% from baseline; SF-36 score improved from baseline; Neurologic parameters maintained or improved from baseline; No re-operations required to modify or remove the implant; and Independent radiographic review confirmed no migration/subsidence, radiolucency, loss of disc height, loss of range of motion, or boney fusion. A Fusion patient was a considered to be a success if, and only if, ALL of the following criteria were met: Items numbered 1-3, above; 4. No re-operations required to modify the fusion site or correct a complication with an implant; and 5. Independent radiographic review confirmed strong evidence of fusion and no motion, visible gaps in fusion mass, loss of disc height, migration/subsidence, implant loosening, halos, or radiolucencies | 60 Months |