Injection Site in Ultrasound-Guided Interscalene Block for Shoulder Arthroscopy

Ultrasound-guided interscalene block is commonly used for postoperative analgesia in patients undergoing shoulder arthroscopy. The location of local anesthetic injection may influence both block efficacy and the incidence of block-related complications. This randomized, double-blind clinical trial compares two different injection sites around the C5-C7 nerve roots using the same local anesthetic dose and volume. The study will assess block success, postoperative analgesia, opioid consumption, diaphragmatic function, and procedure-related complications.