Compression neuropathy of common peroneal nerve/Peroneal nerve palsy
Common peroneal nerve is very vulnerable to compression where it passes around the head of the fibula. Originates from L4, L5, S1.
Sitting cross-legged; prolonged bed rest; leg casts; sitting with posterior calf resting on form surface; external blunt trauma; traction from inversion ankle sprain
Sensory changes (paraesthesia, pain, loss) on anterior and lateral aspect of calf, medial and dorsal aspect of foot and dorsal aspect of hallux and first interspace. Weakness and atrophy of anterior tibial, extensor digitorum longus, extensor hallucis longus and extensor digitorum brevis, if longstanding. Weakness of peroneal muscles increased risk for ankle sprains. If severe foot drop and steppage gait. Percussion on or ‘rolling’ nerve over fibula head may elicit Tinnel’s sign.
Differential diagnosis – L5 radiculopathy; amyotrophic lateral sclerosis; sciatic neuropathy
Most cases self-limited; avoidance of pressure on nerve; measure to decrease local inflammation – NSAID’s; surgical neurolysis