The goal of this pilot study is to assess the feasibility of conducting a randomized controlled trial at a single institution comparing erector spinae plane blockade (ESPB) with liposomal bupivacaine (LB, Exparel) to intravenous (IV) methadone for managing pain in pediatric subjects undergoing adolescent and juvenile idiopathic scoliosis correction. Specifically, the goal is to enroll 15 subjects in each group and to complete data collection for all subjects. If this pilot study is successful, we plan to then design a larger scale study powered to compare specific outcomes between the two groups.

Enrolled subjects will be randomized to one of two groups: one group will receive intra-operative IV methadone as the primary means of controlling post-operative pain while the other group will instead receive intra-operative erector spinae plane blocks (ESPB) with liposomal bupivacaine (LB, Exparel) and bupivacaine hydrochloride as the primary means of controlling postoperative pain. All other aspects of peri-operative management will be standardized. Subjects and the post-operative care team will be blinded to which intervention was performed in order to reduce bias. Upon discharge, subjects will receive a wearable activity monitor and a daily journal in order to record post-discharge data. Subjects will receive weekly phone calls for data collection and then will have a final in-person clinic visit, at which point participation in the study will conclude.

Inclusion Criteria:

• Subjects whose parent(s) or guardian(s) has/have signed and dated the informed consent form (ICF) for the subject to participate in the study
• Patients with a diagnosis of juvenile idiopathic scoliosis (JIS) or adolescent idiopathic scoliosis (AIS) who will have posterior spinal fusion surgery
• Male or female patients 11 to less than 18 years of age on the day of surgery.
• American Society of Anesthesiologists (ASA) Class 1-2.
• Able to adhere to the study visit schedule and complete all study assessments.

Exclusion Criteria:

• Body mass index ≥35 at the time of screening
• Contraindication to regional anesthesia (e.g., abnormal coagulation, infection at site)
• Current opioid use at the time of screening
• Current diagnosis of chronic pain
• Allergy, hypersensitivity, intolerance, or contraindication to any of the study medications
• Administration of liposomal bupivacaine (LB, Exparel)
• Subject/parent/guardian primary language other than English or Spanish
• Inability of patient to verbally express symptoms such as pain and side effects (as in moderate to severe developmental delay)
• A prolonged QTc on preoperative EKG (QTc longer than 450 milliseconds)
• History of Torsades de Pointes
• Renal or hepatic impairment
• Diagnosed active seizure disorder
• Any other condition that causes patient to be ineligible for surgery, i.e. pregnancy.