®
Femoral Nerve Block
Anatomy
The ultrasound guided femoral nerve block is performed at the level of the inguinal crease. The femoral nerve is identified just lateral to the femoral artery and deep to the fascia iliaca (image 1 and 2). The femoral nerve is hyper echoic and oval in shape. It should be noted the femoral vein is medial to the femoral artery. The block should be performed consistently at the level of the common femoral artery. If the patient is obese the panis may be taped to help expose the inguinal crease.
Block Procedure
The femoral nerve block is performed with the patient in the supine position. The ultrasound probe is positioned transversely in the inguinal crease and the common femoral artery is identified. The block needle is inserted lateral to the ultrasound probe using the recommended in plane approach (image 3). The needle is advanced toward the femoral nerve located just lateral to the femoral artery. Nerve stimulation may be used eliciting a motor response of the quadriceps muscle resulting in a patellar twitch. A "pop" may be felt as the needle passes through the fascia iliac. With the needle tip just lateral to the femoral nerve 10-20 ml of local anesthetic is injected. The needle may be moved as necessary to ensure spread of local anesthetic circumferentially around the femoral nerve. The femoral nerve block results in anesthesia of the anterior and medial thigh and knee. This block is performed commonly for total knee replacement and ACL reconstruction.
Image 1
Image 2
Image 3
Every effort has been made to ensure the accuracy of the information presented within this website. The information presented does not constitute medical advice.