An interventional study of femoral and anterior sciatic nerve block and femoral and popliteal sciatic nerve block in Postoperative Pain Management, Postoperative Pain and Analgesia, sponsored by Gaziosmanpasa Research and Education Hospital. Completed at 2 sites in Turkey (Türkiye). Open to participants aged 18 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-08-28.
Sponsored by Gaziosmanpasa Research and Education Hospital · Not applicable, Interventional, and Supportive care
Comparison of Anesthetic and Postoperative Analgesic Efficacy of Femoral and Popliteal Sciatic Block vs Femoral and Anterior Sciatic Block in Ankle Surgery
The sciatic nerve, which arises from the sacral plexus, is the largest nerve in the body. It originates in the posterior region of the thigh in the lumbosacral area and is formed from the anterior branches of spinal nerves from L4 to S3 within the pelvis. It exits the pelvis through the greater sciatic foramen directly below the piriformis and then progresses towards the posterior compartment of the thigh, where it usually divides into the common peroneal nerve and the tibial nerve at the upper corner of the popliteal fossa. Sciatic nerve blocks provide both analgesia and anesthesia in surgeries below the knee, knee surgeries involving the posterior compartment, and foot and ankle surgeries. They can be used alone or in combination with an ipsilateral lumbar plexus block or femoral nerve block to provide surgical anesthesia or analgesia for the entire lower extremity.
Various approaches have been described to perform sciatic nerve block, including anterior and popliteal approaches. The anterior approach to the sciatic nerve can be performed as easily and successfully under ultrasound guidance as the popliteal approach. The anterior approach is advantageous when combined with a femoral nerve block, as it is performed with the patient in the supine position. Due to ease of application and high success rates, peripheral blocks have begun to be incorporated into anesthesia and postoperative analgesia strategies in ankle surgeries. The use of ultrasonography plays a crucial role in increasing the success rate of the block and reducing potential complications.
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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.
Procedure: femoral and anterior sciatic nerve block
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.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.
Procedure: femoral and popliteal sciatic nerve block
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.
Visual Analogue Scale values
Visual Analogue Scale is a scale of 0-10 cm in length, expressed by non-standard verbal descriptors (no pain-unbearable pain..) indicating the limits of pain intensity on both sides, horizontally or vertically.
Time frame: at 1st, 4th,8th 12th ,24th and 48th hours after the surgery
Total amount of opioid requirements
The total tramadol use of the patients in 48 hours will be recorded.
Time frame: within 48 hours after the surgery
Plan to share: Undecided
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Gaziosmanpasa Research and Education Hospital