The common fibular (peroneal) nerve wraps around the neck of the fibula in a superficial fibro-osseous tunnel formed by the fibula (medially), the peroneus longus origin (laterally), and the dense biceps femoris tendon (posteriorly). This tethered position at the fibular neck makes the common fibular nerve the most commonly compressed peripheral nerve in the lower limb. The nerve divides here into its superficial (sensory to dorsal foot) and deep (motor to anterior compartment) branches.
Fibular head compression neuropathy produces foot drop (anterior compartment weakness) and dorsal foot and first web space sensory loss. Common causes include habitual leg crossing, prolonged squatting, cast pressure, fibular fracture, and Baker cyst rupture. EMG localises the lesion to the fibular head. Conservative management with footwear modification and avoidance of compression succeeds in most neuropraxia cases. Intraneural ganglion cysts (the most common intraneural tumour) arise specifically at the fibular head from the superior tibiofibular joint, where a joint capsular defect allows ganglion to track along the articular branch into the common fibular nerve.
Ganglion cyst arising from the superior tibiofibular joint tracks via the articular branch into the common fibular nerve, producing progressive foot drop and peroneal palsy; MRI demonstrates the cyst within the nerve substance at the fibular head, and treatment combines arthroscopic joint decompression to eliminate the source with direct cyst decompression of the nerve without sacrifice of the articular branch.
