A patient sustains a posterior dislocation of the hip and develops foot drop with sensory loss over the dorsum of the foot but intact sensation on the sole and intact eversion. Which nerve is injured?

• A Sciatic nerve trunk
• B Deep peroneal nerve only
• C Superficial peroneal nerve only
• D Common peroneal (fibular) nerve ✓

Explanation

The common peroneal nerve is the most commonly injured nerve in hip dislocation due to its relatively fixed position around the fibular neck. It divides into deep peroneal (dorsiflexion, inversion of foot) and superficial peroneal (eversion, sensory to dorsum). Injury to the common peroneal causes: foot drop (loss of dorsiflexion), loss of eversion (superficial peroneal), and sensory loss on the dorsum of the foot and lateral leg. However, sole sensation (sural and medial/lateral plantar nerves from tibial division of sciatic) and plantarflexion are spared. Full sciatic injury would involve plantarflexion loss and sole sensory loss as well.

Reference: BD Chaurasia's Human Anatomy, 8th ed.

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Written and medically reviewed by the StethoPrep medical team.