Posterior scoliosis correction surgery is associated with sever postoperative pain that necessitate high perioperative opioid doses to alleviate pain . Regional anesthesia techniques such as ultrasound-guided erector spinae plane (ESP) block have emerged as promising strategies for improving postoperative analgesia and reducing opioid consumption.

This secondary analysis evaluates the cost-utility of ESP block compared with total intravenous anesthesia (TIVA) alone in patients scheduled for posterior scoliosis correction surgery. The analysis assesses postoperative quality of life using the EQ-5D-5L instrument value sets from Egyptian population alongside healthcare costs within the early postoperative period.

The study aims to determine whether ESP block provides improved patient outcomes and represents a cost-effective strategy for perioperative pain management in scoliosis surgery

Posterior scoliosis correction surgery is a major orthopedic procedure that involves extensive surgical exposure and is frequently associated with significant postoperative pain. Effective perioperative analgesia is essential to improve patient comfort, facilitate early recovery, and reduce the risk of opioid-related adverse effects.

Ultrasound-guided erector spinae plane (ESP) block is a relatively recent regional anesthesia technique that has shown promising results in improving postoperative analgesia across several surgical procedures. By providing effective thoracic and paraspinal analgesia, ESP block may reduce intraoperative anesthetic requirements and postoperative opioid consumption.

In addition to clinical benefits, evaluating the economic impact of analgesic strategies is increasingly important, particularly in healthcare systems with limited resources. Economic evaluations such as cost-utility analysis allow healthcare decision makers to assess whether new interventions provide sufficient value relative to their costs.

This study aims to evaluate the cost-utility of using ultrasound-guided ESP block with total intravenous anesthesia compared with total intravenous anesthesia (TIVA) alone in patients undergoing posterior scoliosis correction surgery. Health-related quality of life outcomes were assessed using the EQ-5D-5L instrument, and costs were calculated from a healthcare provider perspective during the early postoperative period (8 hours postoperatively )

The findings of this study may provide important evidence regarding the clinical and economic value of ESP block as part of multimodal analgesia strategies in major spine surgery.

((Artificial intelligence-assisted tools were used to generate preliminary drafts of certain descriptive sections. All outputs were critically reviewed, revised, and approved by the study investigators.))

Inclusion Criteria:

• Patients aged 12-25 years,
• scheduled for posterior spinal fixation for scoliosis correction.
• ASA physical status I-III,

Exclusion Criteria:

• ASA status > III,
• refusal to participate,
• multiple congenital anomalies,
• hypersensitivity or contraindication to study medications,
• and body weight < 40 kg.

Patients aged 12-25 years diagnosed with scoliosis and scheduled for posterior spinal fixation surgery were included in the study. All participants were classified as ASA physical status I-III and underwent surgery under general anesthesia in the operating rooms .

individual participant data (IPD) will not be publicly available. Data will be stored securely at the study institution and may be made available upon reasonable request and with institutional approval.