Investigating Superion™ In Spinal Stenosis

The proposed prospective, multi-center, randomized clinical trial is designed to evaluate
the safety and effectiveness of the Superion™ ISS compared to the X-STOP® IPD® device in
healthy adults suffering from at least 6 months of moderate spinal stenosis symptoms who
have been unresponsive to conservative care. The study endpoint is the rate of overall
subject success at 24 months.

Inclusion Criteria:

- Male or female subjects ≥ 45 years of age

- Persistent leg/buttock/groin pain, with or without back pain, that is relieved by
flexion activities (example: sitting or bending over a shopping cart)

- 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)

- Must be able to sit for 50 minutes without pain and to walk 50 feet or more

Exclusion Criteria:

- Axial back pain only

- Fixed motor deficit

- 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

- Unremitting pain in any spinal position

- Significant peripheral neuropathy or acute denervation secondary to radiculopathy

- Lumbar spinal stenosis at more than two levels determined pre-operatively to require
surgical intervention

- Significant instability of the lumbar spine as defined by 3mm translation or 5
degrees angulation

- Sustained pathologic fractures of the vertebrae or multiple fractures of the
vertebrae and/or hips

- Spondylolisthesis or degenerative spondylolisthesis greater than grade 1.0 (on a
scale of 1 to 4)

- Spondylolysis (pars fracture)

- Morbid obesity, defined as Body Mass Index (BMI) greater than 40kg/m2

- Insulin-dependent diabetes mellitus

- Prior surgery of the lumbar spine

- Cauda equina syndrome (defined as neural compression causing neurogenic bowel or
bladder dysfunction)

- Infection in the disc or spine, past or present

- Paget's disease at involved segment or metastasis to the vertebra, osteomalacia, or
other metabolic bone disease

- Tumor in the spine or a malignant tumor except for basal cell carcinoma

- Involved in pending litigation of the spine or worker's compensation related to the
back