Activ-L™ Artificial Disc Treatment of Degenerative Disc Disease in the Treatment of Degenerative Disc Disease

The purpose of this study is to learn whether an investigational device called the Activ-L Artificial Disc is safe and effective in the treatment of degenerative disc disease of the lower (lumbar) spine.

The objective of this clinical study is to evaluate the safety and effectiveness of the Activ-L Artificial Disc for treatment of single-level degenerative disc disease of the lumbar spine in patients who have been unresponsive to at least six months of prior conservative care. The hypothesis of the study is that the Activ-L Disc is non-inferior to the control (the Charité® Artificial Disc \[DePuy Spine\] or ProDisc-L® Total Disc Replacement \[Synthes Spine\]) with respect to the rate of individual subject success at 24 months. Individual subject success is a composite of effectiveness and safety.

Eligibility Criteria:
Inclusion Criteria:

* Age 18 - 60, skeletally mature
* Symptomatic DDD with objective evidence of lumbar DDD, with any of the following characteristics by MRI scan:

  * instability as defined by ≥ 3mm translation or ≥ 5° angulation.
  * osteophyte formation of facet joints or vertebral endplates.
  * decreased disc height of \>2mm as compared to the adjacent level.
  * scarring/thickening of the ligamentum flavum, annulus fibrosis, or facet joint capsule.
  * herniated nucleus pulposus.
  * facet joint degeneration/changes.
  * vacuum phenomenon.
* Single level symptomatic disease at L4/L5 or L5/S1.

  * six months of unsuccessful conservative treatment
* ODI score ≥ 40/100.
* Surgical candidate for an anterior approach to the lumbar spine.
* Back pain at the operative level only, with or without leg pain.
* Back pain VAS score greater than the higher of the two VAS leg pain scores.
* VAS back pain score ≥ 40/100 mm.
* Willing to return for follow-up visits and sign an Informed Consent and HIPAA Authorization.

Exclusion Criteria:

* Previous surgery at any lumbar level, except IDET (Intradiscal Electrothermal Annuloplasty), percutaneous nucleoplasty, or microdiscectomy.
* Chronic radiculopathy, i.e., subject complaint of unremitting pain with a predominance of leg pain symptoms greater than back pain symptoms extending over a period of at least 1 year.
* endplate dimensions smaller than 34.5 mm in medial-lateral and/or 27 mm in the anterior-posterior direction
* Evidence of significant, symptomatic disc degeneration at another lumbar level.
* Preoperative remaining disc height \< 3mm
* Myelopathy.
* Previous compression or burst fracture at the affected level.
* Sequestered herniated nucleus pulposus with migration.
* Mid-sagittal stenosis of \<8mm (by MRI).
* Degenerative or lytic spondylolisthesis \> 3mm.
* Spondylolysis.
* Isthmic spondylolisthesis.
* Lumbar scoliosis (\> 11 degrees of sagittal plane deformity).
* Spinal tumor.
* Active systemic infection or infection at the site of surgery.
* Facet ankylosis or severe facet degeneration.
* Continuing steroid use or prior use for more than 2 months.
* History of allergies to any of the device components.
* Pregnancy or planning to become pregnant within the next 2 years.
* Morbid obesity (BMI \>35).
* Investigational drug or device use within 30 days.
* Osteoporosis or osteopenia
* Metabolic bone disease.
* Leg pain with migrated sequestrum fragment.
* History of rheumatoid arthritis, lupus, or other autoimmune disorder.
* Ankylosing spondylitis.
* History of HIV/AIDS or hepatitis that precludes surgery.
* History of deep vein thrombosis, symptoms of arterial insufficiency, or thromboembolytic disease.
* Current or recent history of illicit drug or alcohol abuse, or dependence as defined as the continued use of alcohol despite the development of social, legal, or health problems.
* Life expectancy \<5 years.
* Chemotherapy within past 5 years or any cancer other than non-melanoma skin cancer treated with curative intent within the past 5 years.
* Prior nephrectomy.
* Abdominal adhesions, endometriosis, inflammatory bowel disease, Crohn's disease, diverticulitis, ulcerative colitis or other abdominal pathology that would preclude abdominal surgical approach.
* Insulin-dependent diabetes.
* Any degenerative muscular or neurological condition that would interfere with evaluation of outcomes, including but not limited to Parkinson's disease, ALS (amyotrophic lateral sclerosis), or multiple sclerosis.
* History of Pelvic Inflammatory Disease.
* Peritonitis.
* Currently in active spinal litigation as a result of medical negligence.
* Prisoner.
* Psychiatric or cognitive impairment that would interfere with the subject's ability to comply with the study requirements, e.g., Alzheimer's disease.