Common fibular nerve injury vs Tibial nerve injury
How to tell Common fibular nerve injury and Tibial nerve injury apart when a board question makes them look alike.
Common fibular injury causes foot drop; tibial injury impairs plantarflexion and plantar sensation.
Side by side
Common fibular nerve injury causes foot drop, weak dorsiflexion/eversion, and sensory loss over dorsum of foot after fibular neck injury.
Tibial nerve injury causes weak plantarflexion/inversion, impaired toe flexion, and plantar foot sensory loss, often with tarsal tunnel or posterior knee injury.
Common fibular nerve injury causes foot drop, weak dorsiflexion/eversion, and sensory loss over dorsum of foot after fibular neck injury.
Tibial nerve injury causes weak plantarflexion/inversion, impaired toe flexion, and plantar foot sensory loss, often with tarsal tunnel or posterior knee injury.
Foot drop with steppage gait, weak dorsiflexion and eversion, numb dorsum of the foot; fibular neck fracture or leg crossing.
Proximal injury (posterior knee trauma): weak plantarflexion and inversion, cannot stand on toes, numb sole. Tarsal tunnel: mainly burning sole numbness.
The repair move
Before naming the answer, force the stem through the separator: Common fibular injury causes foot drop; tibial injury impairs plantarflexion and plantar sensation.
Try a free question
CoreA 35-year-old man with a fibular neck fracture has FOOT DROP (cannot dorsiflex the foot), weakness of foot eversion, and sensory loss over the dorsum of the foot and lateral leg. Plantar flexion is preserved. Which nerve was injured?
Show answer and explanation
Answer: A. Common fibular nerve at the fibular neck. Common fibular (peroneal) nerve passes around the fibular neck where it lies superficially and is extremely vulnerable to injury (fibular fracture, prolonged immobilization with leg externally rotated, tight knee-high cast, leg crossing). Produces FOOT DROP from paralysis of foot dorsiflexors (tibialis anterior, extensor digitorum longus, extensor hallucis longus) and evertors (fibularis longus and brevis), plus sensory loss over dorsum of foot and lateral leg.
Why the other choices are tempting
- B. Tibial nerve in popliteal fossa innervates plantar flexors (gastrocnemius, soleus) and plantar foot sensation; injury causes weak plantar flexion and plantar sensory loss.
- C. Femoral nerve injury affects knee extension and anterior thigh sensation.
- D. Sciatic nerve injury in gluteal region (piriformis syndrome, hip arthroplasty) affects all lower extremity muscles below the knee.
- E. Sural nerve is a pure sensory nerve to the lateral foot.
Flashcards
Tap a card to flip it.
What clue supports Common fibular nerve injury?
Choose Common fibular nerve injury when the stem gives this pattern: Common fibular nerve injury causes foot drop, weak dorsiflexion/eversion, and sensory loss over dorsum of foot after fibular neck injury.
What clue supports Tibial nerve injury?
Choose Tibial nerve injury when the stem gives this contrasting pattern: Tibial nerve injury causes weak plantarflexion/inversion, impaired toe flexion, and plantar foot sensory loss, often with tarsal tunnel or posterior knee injury.
Quick answers
What is the fastest way to tell Common fibular nerve injury from Tibial nerve injury?
Common fibular injury causes foot drop; tibial injury impairs plantarflexion and plantar sensation.
What is the key clue for Common fibular nerve injury?
Common fibular nerve injury causes foot drop, weak dorsiflexion/eversion, and sensory loss over dorsum of foot after fibular neck injury.
What is the key clue for Tibial nerve injury?
Tibial nerve injury causes weak plantarflexion/inversion, impaired toe flexion, and plantar foot sensory loss, often with tarsal tunnel or posterior knee injury.