Comparison of Quadratus Lumborum Block Types

Inclusion Criteria: * Adult Patients undergoing lumbar spinal fusion surgery. * Patients from 40-80 years. Exclusion Criteria: * Recent drug abuse * History of illicit drug use * Chronic pain patients not related to the back lesions. * Opioid tolerant patients. * Patients with any lower extremity weaknesses or deficits. * Patients with American Society of Anesthesiologists (ASA) classification more than 3. * Coagulopathy. * Infection near or in the area of the block. * Pregnant patients. * Uncooperative patients who refuse care which directly effects research participation or clinical care. * If the surgeon reports performing non-typical fusion. * The presence of intraoperative complications like nerve injury or abnormal results of neuromonitoring and extensive dissection. * Vulnerable populations (prisoner, mental impairment / dementia, pregnant, etc.) * Subjects on chronic buprenorphine therapy (either for opioid replacement or pain control)