Safety Study for An Artificial Disc Replacement to Treat Chronic Low Back Pain

This study will be a prospective, open-label, multi-center study that will collect safety data for the minimally invasive PerQdisc Nucleus Replacement Device deployed to reduce chronic low back pain.

This study will be a prospective, open-label, multi-center study that will collect safety data for the minimally invasive PerQdisc Nucleus Replacement Device (NRD). The NRD is used for surgical replacement of a single nucleus pulposus between spinal lumbar discs L1-S1 using an anterior or lateral transpsoas approach. Currently the surgical gold standard involves spinal fusion of the affected vertebral bodies, reducing range of motion and increasing stress on other vertebral bodies. The goal of nucleus replacement is to reduce chronic low back pain by maintaining disc height while preserving range of motion.

Eligibility Criteria:
Inclusion Criteria:

* Patient is skeletally mature and between 22 and 60 years of age.
* Patient has degenerative disc disease (DDD) at a single level between L1 and S1 as confirmed by:History and clinical findings suggestive of symptomatic DDD, Darkened disc on MRI in T2 weighted images, and decreased disc height (decreased greater than 2 mm compared to adjacent cranial or caudal disc height) with minimum disc height of 6 mm.
* Patient has pre-operative back pain VAS score of greater than or equal to 4 (0-10 scale).
* Patient has pre-operative Oswestry Low Back Disability score of greater than or equal to 40 (0-100 scale).
* Patient has received conservative (non-surgical) treatment for back pain for a minimum of 6 months.
* Patient has signed the approved Informed Consent Form.

Exclusion Criteria:

* Patient has had prior lumbar spine surgery.
* Patient has motion of less than 3 degrees on pre-operative lateral flexion/extension radiographs.
* Patient has ankylosing spondylitis or other spondyloarthropathy.
* Patient has isthmic spondylolisthesis or degenerative spondylolisthesis greater than 2 mm.
* Patient has congenital stenosis or epidural lipomatosis.
* Patient has significant facet disease.
* Patient has any known active malignancy.
* Patient has previously undergone immunosuppressive therapy.
* Patient has active local or system infection.
* Patient has been diagnosed with hepatitis, rheumatoid arthritis, lupus erythematosus, or other autoimmune disease, including AIDS, ARC and HIV
* Patient has diabetes mellitus (Type 1 or 2), requiring daily insulin management.
* Patient has osteopenia of the spine (T-score less than 1.0). All females 45 years of age or older and all males 50 or older should have a DEXA scan to confirm this exclusion.
* Patient has morbid obesity defined as body mass index (BMI) more than 40 or a weight of more than 45 kg (100 lbs) over ideal body weight.
* Patient is pregnant or plans to become pregnant during the course of the study.
* Patient has a known allergy to silicone (polymer and balloon material) or barium sulfate (polymer).
* Patient participated in another investigational drug or device study within the past 30 days.
* Patient belongs to a vulnerable population or has a condition such that his/her ability to provide informed consent, comply with follow-up requirements, or provide self assessments is compromised (e.g. developmentally disables, prisoner, chronic alcohol/ substance abuser)
* Patient has a disc herniation
* Patient has a Schmorl's node in the level to be treated

Intraoperative exclusion criteria:

* Protrusion of the 20A imaging balloon up to or beyond the outer margin of the vertebra during the imaging steps.
* Patient has a violated endplate.
* Patient has a disc space that is too narrow.