Comparative Efficacy of Sciatic and Femoral Blocks in Ankle Surgery

First, in the supine position, the USG probe is placed below the inguinal crease. The femoral nerve is located lateral to the femoral artery, above the iliopsoas muscle. Once the needle tip reaches the nerve, simultaneous nerve stimulation is applied. Patellar movement is observed due to quadriceps muscle contraction upon needle placement. After a negative aspiration test, 20 ml of local anesthetic is injected.For the anterior sciatic block, while the patient was in the supine position, a convex ultrasound (USG) probe was placed transversely approximately 10 cm distal to the inguinal ligament. After visualizing the sciatic nerve as a hyperechoic flat structure, the nerve stimulator was set to 1-1.5 mA, 0.1 ms, and 1 Hz. Using an in-plane technique, the block needle was advanced. Upon reaching the sciatic nerve, when contractions in the calf, foot, or big toe continued at a current of 0.3-0.5 mA, 20 ml of 0.5% bupivacaine was administered following a negative aspiration test.

The ultrasound probe is placed transversely at the popliteal crease. The first structure seen is the popliteal artery. Just above and lateral to the artery, the tibial nerve appears as a hyperechoic, oval, and round structure. After identifying the tibial and peroneal nerves, the probe is moved proximally, and it is observed that the nerves join about 5-10 cm above the popliteal crease. The needle is advanced using an in-plane technique. After obtaining the first sciatic nerve stimulation, 20 cc of 0.5% bupivacaine is injected following a negative aspiration test.