70 patients undergoing their first percutaneous transforaminal endoscopic discectomy (PTED) were randomized to receive either 0.3% ropivacaine (n=35) or 0.4% ropivacaine (n=35) for epidural anesthesia. The primary outcomes included intraoperative numeric rating scale (NRS) scores and hip extension level (HEL) measurements. Secondary outcomes involved intraoperative fentanyl usage and postoperative complications. Outcomes were assessed intraoperatively and at 24 hours post-surgery. Overall, the results showed that 0.4% ropivacaine provided significantly better pain control and reduced the need for intraoperative fentanyl compared to 0.3%. However, it was associated with a transient decrease in muscle strength. These findings suggest that 0.4% ropivacaine is a more effective and well-tolerated dose for PTED.