Study Summary

Eighty patients undergoing knee surgeries under spinal anesthesia were randomized to receive either an ultrasound-guided nerve to vastus lateralis (NVL) block or a lateral femoral cutaneous nerve (LFCN) block. The primary outcome of interest was postoperative pain assessed using the numerical rating scale (NRS). Secondary outcomes included time to first rescue analgesia, total morphine consumption within 24 hours, patient satisfaction, block characteristics, adverse events, and hospital length of stay. Outcomes were assessed in the post-anesthesia care unit and at 2, 4, 6, 12, 18, and 24 hours postoperatively. Overall, the results of the study revealed that the NVL block produced a faster onset of sensory blockade, lower pain scores at selected postoperative time points, delayed need for rescue analgesia, and lower opioid consumption compared with the LFCN block. However, although statistically significant, the differences in pain scores did not exceed the predefined minimum clinically important difference, suggesting limited clinical superiority.