It’s the main nerve of the anterior compartment of the thigh. It’s the largest branch of the lumbar plexus and originates from the dorsal sections of the anterior primary rami of L2, L3, L4 nerves. It descends via the psoas major and appears on its lateral border to pass between the psoas and iliacus to goes into the thigh behind the inguinal ligament and lateral to the femoral sheath.

In femoral triangle, it carves into anterior and posterior sections, 2 cm distal to the inguinal ligament. Both sections straddle the lateral circumflex femoral artery. Its motor branches provide iliacus in the abdomen and all the muscles of anterior compartment of the thigh. Its cutaneous branches provide the large cutaneous area on the anterior and medial aspect of the thigh, medial side of leg, and foot. It also provides articular branches to the hip and knee joints.

Anterior section: It produces 2 cutaneous branches and 1 muscular branch:

(a) The cutaneous nerves are: (a) medial cutaneous nerve of the thigh and (b) intermediate cutaneous nerve of the thigh.

(b) The muscular branch provides the sartorius.

Posterior section: It produces 1 cutaneous branch, the saphenous nerve, and 4 muscular branches to provide the quadriceps femoris.

Clinical Significance

Injury of The Femoral Nerve

It’s uncommon but may be injured by a stab, gunshot wounds, or a pelvic fracture. Listed here are the characteristic clinical features:

Motor loss.

  • Poor flexion of the thigh, because of paralysis of the iliacus and sartorius muscles.
  • Inability to extend the knee, because of paralysis of the quadriceps femoris.

Sensory decrease

  • Sensory decline over the anterior and medial aspects of the thigh, as a result of engagement of the intermediate and lateral cutaneous nerves of the thigh.
  • Sensory loss on the medial side of the leg and foot up to the ball of the great toe (first metatarsophalangeal joint), because of engagement of the saphenous nerve.

Femoral Nerve Neuropathy

The primary trunk of the femoral nerve isn’t subject to an entrapment neuropathy . However, it might be compressed by the retroperitoneal tumors. A localized neuropathy of the femoral nerve may happen in diabetes mellitus. Listed here are the characteristic clinical features:

  • Wasting and weakness of quadriceps resulting in significant trouble in walking.
  • Pain and paraesthesia on the anterior and medial aspects of the thigh going down along the medial aspect of the leg and foot along the distribution of the saphenous nerve.