A femoral nerve block is the application of local anaesthetic to the femoral nerve so as to cause the absence of sensation in its distribution.
After identification of relevant landmarks, a needle is inserted 1 cm lateral to the femoral artery pulse and just below the inguinal ligament. It is passed perpendicularly to the skin until paraesthesia is felt by the patient. After aspiration to ensure that the needle does not lie intravascularly, 30-40 ml of 0.5% prilocaine is injected.
A femoral nerve block is advantageous for pain relief in patients with a fractured neck of femur.