TOPS System

Condition: Degenerative Lumbar Spinal Stenosis


Key Inclusion Criteria

  • 35-80 years old
  • Must demonstrate:
    • Degenerative spondylolisthesis or retrolisthesis up to Grade I
    • At least moderate lumbar spinal stenosis
    • Thickening of the ligamentum flavum and/or scarring of the facet joint capsule
  • At least six months of failed conservative treatment prior to surgery

Key Exclusion Criteria

  • More than one motion segment involved in the degenerative pathology that requires a surgical procedure
  • Presence of free fragment disc herniation at the index level or either adjacent level
  • Less than 4 mm of disc height at the index level

Full Study Name

Investigational Device Exemption Application for the Clinical Investigation of the TOPS System (IRB no. 46984)


This study is designed to test the investigational use of the Total Posterior Spine (TOPS) System in patients who have been diagnosed with spine-related conditions. Researchers will compare the results of spinal surgery using the TOPS System (a surgical procedure designed to stabilize the damaged spine segment, rather than to fuse the vertebrae together) to the results of spinal fusion surgery (which is designed to create solid bone between adjoining vertebrae). A spinal implant such as the TOPS System is intended as an alternative to fusion surgery because it stabilizes the vertebrae while still allowing movement of the joints between the vertebrae. Researchers will assess the ability of the TOPS System to restore normal spinal function and prevent future problems caused by participants’ spinal condition. Participants will receive either the TOPS System or fusion surgery.

Phase III

Principal Investigator

Neel Anand, MD