obturator nerve

Question 1

What is the origin and root value of the Obturator nerve

Answer 1

Origin ⇒ Branch of the lumbar plexus, and located on the posterior abdominal wall.

Root value ⇒ Ventral primary rami of L2,L3, L4 (VENTRAL DIVISIONS of ventral rami)

Question 2

Describe the course and relations

Answer 2

• emerges on the medial border of psoas major muscle and descends in the lateral pelvic wall.( related to ovary)
• enters medial side of thigh through obturator canal where it terminates by dividing into
  anterior and posterior divisions.

Question 3

Describe the innervation and branches of the anterior division of obturator nerve.

Answer 3

Articular branch ⇒ Supplies the hip joint

Muscular branch ⇒ Supply the pectineus, adductor longus, adductor brevis, and gracilis

Vascular->femoral artery

Cutaneous ⇒form a subsartorial plexus (branches of ant division of obturator nerve, medial femoral cutaneous nerve, and saphenous nerve) → Supplies the medial side of thigh

Question 4

Describe the innervation and branches of the posterior division of obturator nerve.

Answer 4

Muscular ⇒ Obturator externus, Adductor brevis (if it does not receive supply from the ant. division), Adductor part of Adductor magnus
- passes through hiatus magnus
Genicular branch ⇒ Supplies the articular capsule of the knee joint. After piercing the oblique popliteal ligament it supplies cruciate lig
Vascular: popliteal artery

Question 5

Describe the applied aspects of the obturator nerve

Answer 5

1. Injury of obturator nerve due to pelvic trauma and associated fractures
2. During delivery, compression of the nerve b/w head of fetus and bony structures of the pelvis
3. Ovarian tumors can also can also cause compression of the nerve
4. Neurological disorders can cause adductor spasms → A bilateral obturator neurectomy is performed to relieve the severe adductor spasms.
5. The pain due to disease of the hup joint may be referred to the knee joint and to the medial side of the thigh → common nerve supply of the joint through articular branches of obturator nerve and of cutaneous supply to the medial side of thigh (sub-sartorial plexus)