Fascial entrapment of the sural nerve and its clinical relevance

Sural nerve presents great topographic variability and it is responsible for sensory innervation of the posterolateral side of the distal third of the leg and lateral aspect of the foot. Entrapment of the nerve could be caused by compression due to fascial thickening, while the symptomatology includes sensory alterations and deficits at the nerve distribution area. We report a cadaveric case of a variant sural nerve that presented a distinct entrapment site. A supernumerary sensory branch was encountered originating from the common peroneal nerve, while the peroneal component of the sural nerve was observed to take a course within a fibrous fascial tunnel 3.1 cm in length that caused nerve fixation and flattening. The tension applied to the aforementioned branch was shown to worsen during passive forcible foot plantaflexion and inversion. The etiology, diagnosis and the treatment options are discussed comprehensively.