Indirect vs. Direct Decompression for Treatment of Central Stenosis: RCT

Inclusion Criteria: * Fusion indicated by the treating surgeon. Fusion may be indicated for one or more of the following reasons: * Mobile degenerative spondylolisthesis * Severe vertical foraminal stenosis * Adjacent segment degeneration and/or degenerative disc disease with suspected discogenic pain * One-level central canal stenosis * WITH neurogenic claudication * As measured in preoperative MRI * Oswestry Low Back Pain Disability Questionnaire score \> 35% (18/50) * Failed 3 months of conservative treatment * Willing to give written informed consent and psychosocially, mentally, and physically able to comply fully with protocol, including adhering to follow-up schedule and requirements, and filling out forms Exclusion Criteria: * Multilevel central canal stenosis * Patients with vertebral endplate dimensions that are too small to allow for safe placement of an intervertebral cage * Known allergy to titanium, polyethylene, cobalt, chromium, or molybdenum * Prior surgery at index disc level (discectomy, decompression, or fusion) * History of spinal or vertebral infection of the lumbar spine * History of vertebral fracture of the lumbar spine * Current pregnancy or interest in becoming pregnant over the next 1 year * Active infection-systemic or local * Non-English speakers