Post-Approval Clinical Trial Comparing the Long Term Safety and Effectiveness Coflex vs. Fusion to Treat Lumbar Spinal Stenosis

• Improvement of ODI [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  The primary variable of performance is the assessment of Oswestry Low Back Pain Disability Index (ODI) in both treatment groups at 5 years. It will be assessed if the improvement in ODI since the pre surgery status in the coflex™ group is better than the improvement in the control group.
  
  
• No reoperations, revisions, removals, or supplemental fixation [ Time Frame: 5 years ] [ Designated as safety issue: Yes ]
  Assessment of reoperations, revisions, removals, or supplemental fixation associated with either coflex or control group
  
  
• No major device related complications [ Time Frame: 5 years ] [ Designated as safety issue: Yes ]
  Assessment of major device-related complications, including but not limited to permanent new or increasing sensory or motor deficit at 5 years;
  
  
• Epidural injections [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  Assessment of lumbar epidural injections
  
  

• Zurich Claudication Questionnaire (ZCQ) [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  ZCQ is a scale that measures physical function, symptom severity, and patient satisfaction for patients with spinal stenosis.
  
  
• Quality of Life [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  Assessment of the patient's Quality of Life as measured by SF-12
  
  
• VAS Leg Pain [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  Improvement of the Visual Analog Scale (VAS) for leg pain(on the 100 mm scale) compared to control group
  
  
• VAS Back Pain [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  Improvement of the Visual Analog Scale (VAS) for low back pain(on the 100 mm scale) compared to control group
  
  
• Radiographic Assessment [ Time Frame: 5 years ] [ Designated as safety issue: No ]
  Radiographic Assessment of coflex and control group including range of motion, radiolucency, deveice displacement, spinous process fractures, heterotopic ossification
  
  

The primary objective of this post-approval study is to examine the long-term survivorship of the coflex®. The coflex® Interlaminar Technology is an interlaminar stabilization device indicated for use in one or two level lumbar stenosis from L1-L5 in skeletally mature patients with at least moderate impairment in function, who experience relief in flexion from their symptoms of leg/buttocks/groin pain, with or without back pain, and who have undergone at least 6 months of non-operative treatment. The coflex® is intended to be implanted midline between adjacent lamina of 1 or 2 contiguous lumbar motion segments. Interlaminar stabilization is performed after decompression of stenosis at the affected level(s).