Pediatric spinal fusion (PSF) surgery is a painful procedure that can treat adolescent idiopathic scoliosis (AIS). One technique that can potentially reduce patients' pain levels and need for opioid medication is the ultrasound-guided Erector Spinae Plane Block (ESPB). The ESP block is a technique that involves injecting an anesthetic medication into the muscles of the lower back on both sides of the spine. Previous studies have shown that ESPB application led to a reduction in opioid use, and there is one pediatric case report of ESPB use in two patients undergoing PSF. However, there is still lack of evidence that the ESPB technique is feasible and effective in the pediatric patient population. The present study is designed to be the first randomized controlled trial to evaluate the role of ESPB in pediatric spinal fusion surgery and the role of ESPB within an enhanced recovery pathway.