University of Kansas Medical Center

For All Participants: - Ability to read and speak English to allow for written informed consent, phenotyping, and patient-reported outcomes measures

For All Participants: - Individuals receiving or applying for compensation or disability and other aspects associated with potential secondary gain - Inability to provide written informed consent - Severe physical impairment - Co-morbid medical conditions that may significantly impair physical functional status - Illicit drug or unreported opioid use - Medical or psychiatric conditions that in the judgment of study personnel would preclude participation in this study - Pregnant or nursing - Liver failure - Self-reported liver cirrhosis - Self-reported hepatitis - Severe Cardiovascular disease Inclusion Criteria for Candidates for Lumbar Spine Surgery: - Deemed to be a candidate for primary lumbar spine surgery including but not limited to: lumbar laminectomy, discectomy, and fusion/instrumentation - Diagnostic clinical and radiographic findings including but not limited to: lumbar degenerative disc disease, lumbar disc protrusion, herniation, or extrusion, lumbar spondylosis, lumbar spinal stenosis, lumbar spondylolisthesis or spondylolysis - Willingness to participate in longitudinal follow-up or 6-months after their surgery. Exclusion Criteria for Candidates for Lumbar Spine Surgery: - History of previous lumbar spine surgery - Indication for lumbar spine surgery is due to spinal cancer-related diagnosis - Need for urgent or emergent lumbar spine surgery Inclusion Criteria for Candidates with Lumbar Failed Back Surgery Syndrome: - Chronic low back pain (+/- leg pain) for >= to 6 months duration after lumbar spine surgery (with or without instrumented fusion) - Low back pain severity is moderate to severe (Numerical Rating Scale [NRS] Score >=4) Exclusion Criteria for Candidates with Lumbar Failed Back Surgery Syndrome: - Have a structural spinal lesion that would make them a current candidate for a revision lumbar spine surgery Inclusion Criteria for Healthy Volunteers: - No major diseases or diagnoses influencing pain or function Exclusion Criteria for Healthy Volunteers: - No chronic pain condition - Score 3 or greater on the 2011 FM Survey Criteria (i.e. individuals with very mild fatigue or sleep problems will be allowed to participate as this is extremely common in the general population)