Flashcards in Obturator Nerve Deck (23):
What are the nerve roots of the obturator nerve?
What are the motor functions of the obturator nerve?
Innervates the medial (adductor compartment) of the thigh
What are the sensory functions of the obturator nerve?
Cutaneous branch innervates the skin of the medial thigh
What is the obturator nerve formed by?
The anterior divisions of the 2nd, 3rd and 4th lumbar nerve
What is the anatomical course of the obturator nerve?
It descends through the fibres of the psoas major muscle and emerges from its medial border, running posteriorly to the common iliac arteries and laterally along the pelvic wall to the obturator foramen
It enters the thigh through the obturator canal
What happens to the obturator nerve once it’s entered the thigh?
It splits into anterior and posterior divisions
What course does the anterior division of the obturator nerve take?
It descends between the adductor longus and adductor brevis muscles, towards the femoral artery
What branches does the anterior division give off?
To the adductor longus, adductor brevis, and gracilis
In rare cases, it also gives off a branch to the pectineus muscle
What does the anterior division of the obturator nerve become?
The cutaneous branch of the obturator nerve
What does the obturator nerve become the cutaneous nerve of the obturator nerve?
When it pierces the fascia lata
What course does the posterior division of the obturator nerve take?
It descends through the obturator externus muscle before passing anteriorly to the adductor magnus and giving off branches to supply it
What muscles does the obturator nerve innervate?
What does the adductor longus do?
What does the adductor brevis do?
What does the adductor magnus do?
Adductor part adducts and flexes thigh
Hamstring part extends thigh
What does the gracilis do
What does the obturator externus do?
Laterally rotates thigh
What does the cutaneous branch of the obturator nerve supply?
The skin of the middle part of the medial thigh
How can the obturator nerve be damaged?
During surgery involving the pelvis or abdomen
What are the symptoms of obturator nerve damage?
Numbness and paraesthesia on the medial aspect of the thigh
Weakness in adduction of the thigh
Posture and gait problems
When is obturator nerve block used?
In the management of pain after lower limb surgery, or for chronic hip pain
How is obturator nerve block induced?
The anaesthetic is injected inferior to the pubic tubercle and lateral to the tendon of the adductor longus muscle