Comparison of ultrasound-guided anterior versus transgluteal sciatic nerve blockade for knee surgery

BACKGROUND: Ultrasound-guided sciatic nerve block, in combination with femoral nerve and lateral femoral cutaneous nerve blocks, is frequently used to induce anesthesia for lower limb surgery. The anterior approach to the sciatic nerve is performed in the supine position and repositioning of the patient between injections is avoidable. We compared the relative utility and efficiency of anterior versus transgluteal sciatic nerve blocks in conjunction with femoral nerve and lateral femoral cutaneous nerve blockade. MATERIALS AND METHODS: Twenty-four patients were enrolled in this prospective double-blind randomized study and were randomly divided into two equal groups: Anterior (Group A) and transgluteal (Group T). We evaluated the following parameters: ultrasound view quality, procedural duration, onset time to block, quality of anesthesia during surgery and postoperative analgesia, required administration of supplemental sedation or narcotics during surgery, amount of pethidine administered within 24 hours post surgery, and overall patient satisfaction. RESULTS: There were no significant differences between patient groups with regard to the demographic data, onset time to block, quality of ultrasound view, use of narcotics to augment the anesthesia during surgery, and patient satisfaction. Although procedural completion time for the sciatic injection alone was shorter in Group T, the total completion time of all blocks together was significantly less in Group A. CONCLUSION: Ultrasound-guided anterior blockade of the sciatic nerve has advantages over the transgluteal approach — it provides efficient anesthesia and results in excellent patient satisfaction.