Medial plantar digital proper nerve syndrome (Joplin's neuroma)--typical presentation.

Joplin's neuroma, a painful pedal neuralgia, is a benign enlargement of the medial plantar digital proper nerve. The pathology is described as a degenerative process of the nerve characterized by perineural fibrosis. This clinical entity is thought to be caused by 1) trauma, 2) biomechanical imbalances, 3) entrapment, and 4) pinch callus resulting from interphalangeal joint accessory bone. This article illustrates typical presentation of the syndrome, taking into consideration the first two etiologic factors, which have not been reported in the literature.