Nerves - Femoral

Question 1

What nerve roots make up this nerve?

Answer 1

L2-L4

Question 2

Motor function?

Answer 2

Innervates anterior thigh muscles:

1) Flexors - pectineus, iliacus, sartorius.
2) Extensors - quadriceps femoris, rectus femoris, vastus lateralis, vastus medialis, vastus intermedius.

Question 3

Sensory function?

Answer 3

Supplies anterior cutaneous branches to the anteromedial thigh.

It also supplies the saphenous nerve to the medial side of the leg.

Question 4

Pathway of the femoral nerve

Answer 4

Travels inferior to the psoas major muscle of the posterior abdominal wall. It supplies branches to the pectineus and iliacus muscles, prior to entering the thigh.

The femoral nerve then passes under the inguinal ligament to enter the femoral triangle. Within the femoral triangle, the nerve is located lateral to the femoral artery and vein (that are enclosed within the femoral sheath).

The femoral nerve then branches off as:

i) anterior cutaneous branches
ii) muscular branches
iii) saphenous nerve

It then exits prior to reaching the adductor hiatus.

The saphenous nerve innervates the medial aspect of the leg and foot.

Question 5

Clinical relevance: stripping of the saphenous vein

Answer 5

The saphenous vein is often stripped in people with problematic varicose veins. The long saphenous vein is accompanied with the nerve.

Damage to the saphenous nerve in this procedure can lead to paraesthesia, or complete loss of sensation in the medial leg.

Question 6

Clinical relevance: femoral nerve block

Answer 6

Femoral nerve block (in combination with sciatic nerve block) may be indicated in patients requiring lower limb surgery who cannot tolerate a general anaesthesia.

A femoral nerve block can be used peri- and post-operative analgesia in patients with a fractured neck who cannot tolerate particular analgesics.