Femoral nerve

Last revised by Assoc Prof Craig Hacking on 26 Aug 2019

The femoral nerve is a large nerve arising from the lumbar plexus and one of two major nerves supplying the lower limb.

It arises from posterior divisions of L2-L4 roots of the lumbar plexus.

  • lies above iliacus, outside and lateral to the femoral sheath
  • sends a branch to pectineus
  • the lateral femoral circumflex artery separates the nerve into superficial and deep divisions
  • the terminal branch of the deep division reaches the apex of the femoral triangle to become the saphenous nerve

See the article: femoral triangle

Branches of the superficial division include:

  • the nerve to sartorius
  • medial cutaneous nerve of thigh contributes to subsartorial plexus (with branches of the obturator and saphenous nerves)
  • the intermediate cutaneous nerve of thigh
  • sympathetic vasomotor supply to blood vessels

Branches of the deep division include:

The femoral nerve provides motor supply to the anterior compartment of the thigh and sensory supply to the hip, anterior and medial thigh, knee, and medial leg (as the saphenous nerve).

  • femoral nerve splits into two or three separate slips within the psoas muscle but unites to descend as a single bundle 2
  • accessory femoral nerve: fibers arise separately in lumbar plexus, passes anterior to femoral nerve, may terminate as saphenous nerve / cutaneous branch
  • femoral branch replacing lateral femoral cutaneous nerve which usually branches directly off lumbar plexus
  • saphenous nerve terminating  at knee with distribution replaced by branch of the tibial nerve

Femoral nerve is endangered by trauma. Injury results in weakness of knee extension and numbness overlying the anterior/medial thigh and medial leg.

The femoral nerve is responsible for the patellar tendon reflex (tests L3-L4 spinal component)

ADVERTISEMENT: Supporters see fewer/no ads

Cases and figures

  • Figure 1: femoral nerve
    Drag here to reorder.
  • Figure 2: lumbar plexus labeled
    Drag here to reorder.
  • Figure 3: femoral triangle (diagram)
    Drag here to reorder.
  • Updating… Please wait.

     Unable to process the form. Check for errors and try again.

     Thank you for updating your details.