Liposomal bupivacaine versus standard ropivacaine for pain control in adults receiving continuous supraclavicular brachial plexus blocks for open elbow arthrolysis: study protocol for a randomised controlled non-inferiority clinical trial.

introductionOpen elbow arthrolysis effectively treats post-traumatic elbow stiffness, but severe postoperative pain during early rehabilitation impedes recovery. Continuous brachial plexus blocks, though effective, face limitations such as catheter displacement and infection risks. Liposomal bupivacaine, an ultra-long-acting local anaesthetic, offers prolonged analgesia and may circumvent these challenges. This study aims to compare the analgesic efficacy of a single-dose liposomal bupivacaine supraclavicular block versus continuous ropivacaine infusion in patients undergoing open elbow arthrolysis. METHODS AND ANALYSIS: This single-centre, randomised, double-blind, non-inferiority trial will enrol 72 adults (ASA I-III，the American Society of Anesthesiologists physical status classification for preoperative risk) scheduled for open elbow release surgery. Participants will be randomised (1:1) to receive either a single supraclavicular block with 10 mL liposomal bupivacaine plus 10 mL 0.5% ropivacaine followed by saline infusion (liposomal bupivacaine group) or continuous catheter infusion with 20 mL 0.5% ropivacaine followed by 0.2% ropivacaine infusion (control group). The primary outcome is the weighted area under the curve (AUC) of Numerical Rating Scale (NRS) pain scores during functional exercises within 72 hours postoperatively. Secondary outcomes include resting NRS scores, sleep quality (Pittsburgh Sleep Quality Index), rehabilitation metrics (range of motion, grip strength), recovery quality (Quality of Recovery -15) and long-term functional outcomes (Quick Disabilities of the Arm, Shoulder and Hand scores, Quick-DASH scores) at 2 weeks, 6 weeks and 12 weeks. Non-inferiority will be established if the upper 95% confidence limit of the AUC difference is ≤1.3. Statistical analyses will employ intention-to-treat principles with SPSS V.24.0. ETHICS AND DISSEMINATION: Ethical approval was granted by Beijing Jishuitan Hospital Ethics Committee (K2025-213-00). The trial is registered with the Chinese Clinical Trial Registry (ChiCTR2500103911). Results will be disseminated via peer-reviewed journals, contributing evidence on liposomal bupivacaine's role in perioperative analgesia and rehabilitation for elbow surgery. TRIAL REGISTRATION NUMBER: Chinese Clinical Trial Registry (ChiCTR ID provided on acceptance).