FDA reclassified so all 522 studies were stopped,

The purpose of the Post-Market Surveillance study is to evaluate safety.

Paradigm Spine Dynamic Stabilization System (DSS) study is a prospective, multi-center, literature controlled study.

Inclusion Criteria:

• Patient is skeletally mature (21-85 years old).
• Patient has degenerative spondylolisthesis (Grade 1-3) with objective evidence of neurologic impairment, kyphosis, and/or failed previous fusion (pseudarthrosis) at index level.
• Capable and willing to comply with the requirements unique to the study, adhere to the post-operative treatment and management program, and return for required follow-up examinations.
• Surgeon has determined that DSS™ System is an appropriate treatment for the patient without regard to the study.

Exclusion Criteria:

• The need for interbody cages, allograft, or any other assistance during surgery. Device is only to be used with autograft per FDA approved indications.
• Any medical, mental or surgical condition precluding the potential benefit of spinal surgery or surgery in general.
• Acute or chronic systemic, spinal or localized infections.
• Active, severe systemic and metabolic diseases.
• Obesity defined as Body Mass Index > 35.
• Subject is pregnant or interested in becoming pregnant in the next 36 months.
• Dependency on pharmaceutical drugs, drug abuse, or alcoholism.
• Lack of patient cooperation.
• Foreign body sensitivity to the implant material.
• Degenerative scoliosis greater than 25 degrees.
• Grade 4 degenerative spondylolisthesis (>75% slip).
• Significant osteopenia A screening questionnaire for osteopenia, SCORE (Simple Calculated Osteoporosis Risk Estimation), will be used to screen patients who require a DEXA bone mineral density measurement. If DEXA is required*, exclusion will be defined as a DEXA bone density measured T score of ≤ -1.0 (The World Health Organization definition of osteopenia).
• Soft tissue deficit not allowing wound closure.
• Congenital abnormalities, tumors or other conditions that would prevent secure component fixation that has the potential to decrease the useful life of the device.
• Inadequate pedicles or vertebral body geometry of the thoracic, lumbar and sacral vertebrae.
• Bony lumbar spinal stenosis not related to the primary degenerative spondylolisthesis indication.
• Pars defect.
• Clinically compromised vertebral bodies at affected level due to current or past trauma.
• Prisoner or ward of the state.
• Currently in litigation regarding a spinal condition.
• Known allergy to titanium, titanium alloys, CoCrMo, polyethylene or MR contrast agents.
• Is currently involved in a study of another investigational product for similar purpose.

6 months