A patient presents with inability to evert the foot, loss of sensation over the dorsum of the foot (excluding the first web space and the medial border), and foot drop. The nerve most likely injured is:

• A Deep peroneal (anterior tibial) nerve
• B Superficial peroneal nerve
• C Tibial nerve in the popliteal fossa
• D Common peroneal nerve at the fibular head ✓

Explanation

The common peroneal nerve (common fibular nerve) wraps around the neck of the fibula and divides into the superficial and deep peroneal nerves. Injury at the fibular head (most common site, due to fracture, pressure, or cast) causes combined deficit: foot drop (from loss of deep peroneal innervation to tibialis anterior, extensor digitorum, extensor hallucis longus) PLUS loss of eversion (superficial peroneal innervation to peroneus longus and brevis) PLUS sensory loss over dorsum of foot and lateral leg. A purely superficial peroneal injury would spare foot dorsiflexion; a purely deep peroneal injury would spare eversion.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.