ESP Block Vs. QIPB for Lumbar Stabilization Surgery

This randomized clinical trial aims to evaluate and compare the analgesic efficacy and functional outcomes of the quadro-iliac plane block (QIPB) and the erector spinae plane block (ESPB) in patients undergoing lumbar stabilization surgery. The primary outcome is the Numeric Rating Scale (NRS) within the first 48 hours after surgery. Secondary outcomes include postoperative total opioid consumption, incidence of quadriceps motor block, time to first ambulation, block performance time, falls, length of hospital stay, block-related complications (hematoma, local anesthetic systemic complications, vascular puncture, and infection), patient satisfaction assessed using a Likert scale, and incidence of postoperative nausea and vomiting.

Inclusion Criteria: * Age between 18 and 80 years * American Society of Anesthesiologists physical status I-III * Scheduled for elective primary lumbar stabilization surgery * Surgery planned under general anesthesia * Ability to understand and use the Numeric Rating Scale * Written informed consent provided Exclusion Criteria: * Refusal to participate * Revision lumbar stabilization surgery * Contraindication to regional anesthesia * Contraindication to peripheral nerve/plane block * Known allergy to local anesthetics or study drugs * Coagulopathy or anticoagulant use incompatible with neuraxial/regional -anesthesia * Infection at the block injection site * Pre-existing neurological deficit involving the lower extremities (unrelated to t-he current spinal pathology) * Peripheral neuropathy * Chronic opioid use * Cognitive impairment or inability to communicate reliably * Severe hepatic or renal failure * Body mass index \> 35 kg/m2 * Pregnancy