Study Summary

46 patients were randomized to receive either an interscalene block (ISC) or a shoulder anterior capsule block (SHAC). Due to early discharge before 24 hours and one block failure, 40 patients were included in the final analysis, with 20 patients analyzed per group. The primary outcome of interest was postoperative pain score at 8 hours, measured using the numeric rating scale. Secondary outcomes included pain scores at additional postoperative time points, intraoperative and 24 hour postoperative fentanyl consumption, early postoperative motor strength, and patient and surgeon satisfaction. Outcomes were assessed from 1 hour to 24 hours postoperatively. Overall, the results of the study revealed that interscalene block provided significantly better postoperative analgesia at all assessed time points, required substantially less opioid consumption, and resulted in higher patient satisfaction, despite demonstrating a worse early motor function compared to the shoulder anterior capsule block.