A Study of the In-Space Device for Treatment of Moderate Spinal Stenosis

A Multi-Center Randomized Controlled Trial of the In-Space Compared to X STOP® for Treatment of Moderate Degenerative Lumbar Spinal Stenosis

The purpose of this study is to evaluate the safety and effectiveness of the In-Space compared to the X STOP Interspinous Process Distraction (IPD) device ("X STOP") for the treatment of patients experiencing intermittent neurogenic claudication secondary to moderate degenerative lumbar stenosis at one or two lumbar levels.

Inclusion Criteria:

• ≥ 50 years in age
• Leg/buttock/groin pain, with or without back pain, that can be completely relieved by flexion such as when sitting in a chair.
• Zurich Claudication Questionnaire Score ≥ 2.0,
• Neurogenic intermittent claudication secondary to moderate lumbar spinal stenosis
• Has completed at least 6 months conservative therapy

Exclusion Criteria:

• Axial back pain only without leg/buttock/groin pain
• Has had any prior lumbar spine surgery at any level
• Significant scoliosis, defined as Cobb angle > 10°
• Spondylolisthesis > Grade 1 or isthmic spondylolisthesis at affected level
• Osteoporosis
• Morbid obesity, defined as BMI > 40 kg/m2