Advanced Obturator Nerve Quiz

Q1. What motor deficit most strongly suggests a significant obturator nerve lesion?

• Weakness of knee extension
• Weakness of toe extension
• Loss of ankle plantarflexion
• Weakness of thigh adduction

Q2. Why might thigh adduction not be completely abolished after an obturator nerve lesion?

• Other muscles with non-obturator innervation can still contribute to adduction
• The femoral nerve always replaces the obturator nerve
• Adduction is performed only by quadriceps
• The obturator nerve regenerates immediately

Q3. Why is the obturator nerve vulnerable during pelvic lymph node dissection?

• It is enclosed within the rectus sheath
• It remains entirely within the vertebral canal
• It lies inside the abdominal aorta
• It runs through the obturator region near pelvic vessels and lymphatic tissue

Q4. Why can pelvic masses or surgery cause both medial thigh pain and adductor weakness?

• The obturator nerve is purely sensory
• The medial thigh is supplied only by the sciatic nerve
• The obturator nerve carries both sensory and motor fibers before entering the thigh
• Adductors are supplied exclusively by the femoral nerve

Q5. How does adductor brevis serve as an anatomical landmark for the obturator nerve?

• The entire nerve lies superficial to adductor longus
• The anterior and posterior divisions pass on opposite sides of adductor brevis
• The nerve terminates before reaching adductor brevis
• Both divisions pass through the muscle's tendon

Q6. Why can obturator nerve irritation produce referred pain at the knee?

• It directly innervates quadriceps
• It supplies the patellar tendon reflex
• The nerve may carry articular sensory fibers from the knee
• It is the main cutaneous nerve of the lateral leg

Q7. What anatomical relationship makes the obturator nerve different from the femoral nerve as they leave the posterior abdominal wall?

• Femoral emerges medially and obturator laterally
• Both descend on the anterior surface of psoas major
• Both pass through the obturator canal
• Obturator emerges medially into the pelvis, while femoral emerges laterally toward the inguinal ligament

Q8. Why can obturator nerve damage occur during difficult childbirth or pelvic procedures?

• It is contained in the femoral sheath
• It lies within the uterine cavity
• It passes through the inguinal canal
• Its pelvic sidewall course exposes it to compression or surgical injury

Q9. Which finding would argue against an isolated obturator neuropathy?

• Pain near the medial thigh
• Marked quadriceps weakness with a reduced patellar reflex
• Weak thigh adduction
• Medial thigh sensory disturbance

Q10. Which statement best integrates the anatomy of the obturator nerve?

• It is an L2 to L4 anterior-division nerve passing through the obturator canal to the medial thigh
• It is an L1 sensory nerve traversing the inguinal canal
• It is a sacral motor nerve exiting through the greater sciatic foramen
• It is an L2 to L4 posterior-division nerve supplying quadriceps