Comparison of Ropivacaine 0.5% and Ropivacaine 0.75% in Proximal Popliteal Sciatic Block for Foot Surgeries

Background: Proximal popliteal sciatic nerve block is widely used for foot surgery to provide effective perioperative analgesia and reduce postoperative opioid requirements. The concentration of ropivacaine may influence block onset, duration, motor recovery, and postoperative analgesia. This study compared 0.5% and 0.75% ropivacaine for proximal popliteal sciatic nerve block in patients undergoing foot surgery. Materials and Methods: This prospective, randomized, double-blind comparative interventional study included 50 adult patients undergoing elective foot surgery. Participants were randomly allocated into two equal groups: Group A received 0.5% ropivacaine and Group B received 0.75% ropivacaine. Sensory and motor block characteristics, duration of postoperative analgesia, pain scores, time to first rescue analgesic, rescue analgesic consumption, and patient satisfaction were assessed. Results: Baseline demographic characteristics and duration of surgery were comparable between groups. Sensory block onset was significantly faster with 0.75% ropivacaine (9.23 ± 1.61 vs. 14.16 ± 1.84 minutes; p < 0.001). Sensory block duration (10.23 ± 0.82 vs. 8.78 ± 0.68 hours; p < 0.001), motor block duration (8.81 ± 0.60 vs. 7.54 ± 0.56 hours; p < 0.001), and postoperative analgesia duration (10.29 ± 0.74 vs. 8.32 ± 0.79 hours; p < 0.001) were significantly longer with 0.75% ropivacaine. Pain scores at 4 and 8 hours were significantly lower, time to first analgesic request was longer (10.79 ± 0.83 vs. 8.76 ± 0.69 hours; p < 0.001), and rescue analgesic requirement was lower (p = 0.03) in Group B. Conclusion: In proximal popliteal sciatic block for foot surgery, 0.75% ropivacaine provided faster onset and longer-lasting postoperative analgesia with reduced rescue analgesic requirement compared with 0.5% ropivacaine.