Femoral Nerve Block

The important landmarks for this block include the inguinal crease and femoral artery (FA).

An anatomic study has shown the femoral nerve (FN) to be widest and most superficial at the level of the inguinal crease where it can be found immediately lateral to the artery 71% of the time.

A. Surface anatomic landmarks relevant to the FN block. IC, inguinal crease; A, femoral artery. An “X” is placed lateral to the FA to identify the site for needle insertion (left inguinal region shown). B. Illustration of the relationship of the FN, FA, and femoral vein below the inguinal ligament. Reproduced from Perlas A. Ultrasound Guided Femoral Nerve Block. In: Chelly JE, ed. Peripheral Nerve Blocks: A Color Atlas. 3rd ed. Philadelphia: Lippincott Williams & Wilkins, 2009: 295, with permission.

Approach and Technique

With a high frequency linear transducer positioned at the level of the inguinal crease and oriented parallel to the inguinal ligament, the FA is identified.