Closed Rupture of the Extensor Hallucis Longus (EHL) Tendon Due to Forced Traumatic Hyperflexion of the Hallux: A Case Report.

A closed spontaneous rupture of the extensor hallucis longus (EHL) tendon is an infrequent yet challenging clinical occurrence, typically associated with systemic conditions (diabetes mellitus or rheumatoid arthritis). A closed EHL rupture, however, exists but is only reported as scattered cases in the literature. This article presents a unique case of a traumatic EHL tendon rupture in a patient without underlying predisposing factors. A 66-year-old woman, previously healthy, presented with an inability to dorsiflex her big toe following trauma, showcasing the clinical triad of pain, edema, and deficit in big toe extension. Magnetic resonance imaging confirmed a 5.9 cm EHL tendon gap that was treated by primary end-to-end repair of the ruptured tendon. The aim of this case report is to provide an overview of the literature available concerning the classification and treatment of EHL rupture and to assist in the early diagnosis and treatment of this rare condition.