Ultrasound-guided femoral nerve block


The positioning of the patient is identical to that in the conventional technique. The probe is applied roughly in the direction of the inguinal ligament, making it possible to identify characteristic anatomic structures: the femoral vein and artery and the femoral nerve in cross-section. The latter almost always appears as a hyperdense triangle lateral to the artery. The nerve is covered by the iliac fascia, which shows up in the ultrasonic image with a fine, white double contour.


The Technique

In principle, the femoral block can be carried out with both the long and short axis technique. We have come to prefer puncture on the long axis, where the needle is advanced under visual control to the lateral corner of the „femoral“ triangle. Penetration of the iliac fascia is mandatory here. After a visual check for correct distribution of a small test dose in the area of the nerves below the fascia, the rest of the local anaesthetic can be given under visual control.


Sonoanatomic Landmarks

Femoral artery and femoral vein, iliac fascia, iliopsoas muscle

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