Peroneus quartus muscle and ankle pain

Summary The peroneus quartus is a supernumerary muscle that has been well described in anatomical studies. It plays an important role in the development of pain, swelling and functional impairment of the ankle joint. A certain diagnosis can be established by magnetic resonance imaging (MRI) or surgery. Treatment options include fasciotomy or complete excision of the muscle. This case report aims to contribute to the knowledge of this pathology.