Superion^™ Interspinous Spacer in Lumbar Spinal Stenosis

You may be eligible if:

1. Male or female subjects greater than or equal to 45 years of age.
2. Persistent leg/buttock/groin pain, with or without back pain that is relieved by flexion activities (example: sitting or bending over a shopping cart).
3. Diagnosis of degenerative spinal stenosis of the lumbar spine, defined as the narrowing of the midline sagittal spinal canal (central) and/or narrowing between the facet superior articulating process (SAP), the posterior vertebral margin (lateral recess), and the nerve root canal (foraminal).
4. Must be able to sit for 50 minutes without pain and to walk 50 feet or more.
5. Subjects who are able to give voluntary, written informed consent to participate in this clinical investigation and from whom consent has been obtained.
6. Subjects, who, in the opinion of the Clinical Investigator, are able to understand this clinical investigation, cooperate with the investigational procedures and are willing to return to the hospital for all the required post-treatment follow-ups.

You may not be eligible if you:

1. Axial back pain only.
2. Fixed motor deficit.
3. Diagnosis of lumbar spinal stenosis which requires any direct neural decompression or surgical intervention other than those required to implant the control or experimental device.
4. Unremitting pain in any spinal position.
5. Significant peripheral neuropathy or acute denervation secondary to radiculopathy.
6. Lumbar spinal stenosis at more than two levels.
7. Significant instability of the lumbar spine as defined by 3-mm translation or 5-degrees angulation.
8. Sustained pathologic fractures of the vertebrae or multiple fractures of the vertebrae and/or hips.
9. Spondylolisthesis or degenerative spondylolisthesis greater than grade 1.0 (on a scale of 1 to 4).
10. Spondylolysis (pars fracture).
11. Morbid obesity, defined as Body Mass Index (BMI) greater than 40kg/m2.
12. Insulin-dependent diabetes mellitus.
13. Significant peripheral vascular disease (diminished dorsalis pedis or tibial pulses).
14. Prior surgery of the lumbar spine.
15. Cauda equina syndrome (defined as neural compression causing neurogenic bowel or bladder dysfunction).
16. Infection in the disc or spine, past or present.
17. Evidence of active (systemic or local) infection at time of surgery.
18. Active systemic disease such as AIDS, HIV, hepatitis, etc.
19. Paget's disease at involved segment or metastasis to the vertebra, osteomalacia, or other metabolic bone disease.
20. Currently undergoing immunosuppressive therapy or long-term steroid use.
21. Known allergy to titanium or titanium alloys.
22. Tumor in the spine or a malignant tumor except for basal cell carcinoma.
23. Known or suspected history of alcohol and/or drug abuse.
24. Prisoner or transient.
25. Life expectancy less than two years.
26. Angina, active rheumatoid arthritis, or any other systemic disease that would affect the subject's welfare or outcome of the clinical investigation.
27. Any significant psychological disturbance past or present, psychotic or neurotic that could impair the consent process or ability to complete subject self-report questionnaires.
28. Involved in pending litigation of the spine or worker's compensation related to the back.
29. Enrolled in the treatment phase of another drug or device clinical investigation (currently or within past 30 days).