Prospective, multicenter, randomized controlled clinical study examining functional improvement in lumbar spinal stenosis (LSS) patients with neurogenic claudication who are treated with the MILD procedure plus conventional medical management (CMM) compared to those treated with CMM alone, as the control. Subjects in the control group are able to crossover and receive MILD after completion of 12-month follow-up. The study will provide objective functional improvement data for patients treated with the mild Procedure as first-line therapy in a real-world setting.

The study will follow participants treated in the MILD plus CMM group and crossover participants for up to 5 years on annual bases.

Inclusion Criteria:

• Patients experiencing neurogenic claudication symptoms for at least 3 months duration.
• LSS with neurogenic claudication
• Radiologic evidence of LSS with unilateral or bilateral ligamentum flavum ≥ 2.5mm confirmed by pre-op MRI or CT performed within 12 months of baseline visit.
• Patients with comorbid conditions commonly associated with spinal stenosis, such as osteophytes, facet hypertrophy, minor spondylolisthesis (Grade I without instability), foraminal stenosis, and/or disk protrusion may be included unless the treating physician has determined that the condition is too advanced.
• Stable opioid intake with no change during 30 days prior to enrollment.
• Available to complete all follow-up visits.

Exclusion Criteria:

• ODI Score < 31 (0-100 ODI Scale).
• NPRS Score < 5 (0-10 NPRS Scale).
• Lumbar epidural injections during eight weeks prior to study enrollment.
• Baseline analgesic medication greater than 90 milligram morphine equivalent (MME).
• Prior surgery at the same treatment level.
• Previously received interspinous spacer at the same treatment level.
• Previously received intradiscal procedure at the same treatment level.
• Previously received vertebral augmentation procedure at the same treatment level.
• Previously received the MILD procedure at the same treatment level.
• Received radiofrequency ablation at the same or the adjacent levels within 6 months prior to study enrollment.
• History of spinal fractures with current related pain symptoms.
• Grade II or higher spondylolisthesis.
• Motor deficit or disabling back and/or leg pain from causes other than LSS neurogenic claudication (e.g. acute compression fracture, metabolic neuropathy, or vascular claudication symptoms, etc.).
• Unable to walk ≥ 10 feet unaided before being limited by pain. In this context, 'unaided' means without the use of a cane, walker, railing, wall, another person or any other means of walking assistance.
• Previously randomized and/or treated in this clinical study.
• Epidural lipomatosis (if it is deemed to be a significant contributor of canal narrowing by the physician).
• On (or pending) Workman's Compensation or known to be considering litigation associated with back pain.