Lower Extremity Blocks: Popliteal Sciatic Block

Abstract

Sciatic nerve blockade at the level of the popliteal fossa is a safe and reliable method for providing anesthesia and/or analgesia to the lower extremity below the knee, with the exception of the medial aspect of the leg, ankle and foot. Complete anesthesia and/or analgesia below the knee can be accomplished with supplemental saphenous nerve blockade. Sciatic nerve blockade at this level spares the hamstring muscle allowing the patient to ambulate. The procedure can be performed from a posterior, lateral or medial approach using ultrasound and/or nerve stimulation. Ultrasound imaging allows dynamic visualization of the sciatic nerve as it branches into the tibial and common peroneal nerves. The operator can also observe circumferential spread of injected local anesthetic around the target nerve(s). Nerve stimulation can also be used for sciatic nerve blockade at the popliteal fossa. This technique relies on the operator to identify the motor response as the stimulating needle approaches the target nerve. If prolonged analgesia is desired, a peripheral nerve catheter can easily be placed and secured at this location.