第5中足骨基部：骨折か異形成か？

Accessory ossicles are anatomical variants that may lead to foot pain, particularly in individuals with a history of trauma, and are often overlooked. We present a case of a 21-year-old male patient with a history of inversion injuries who was initially misdiagnosed with an avulsion fracture of the fifth metatarsal. Following multiple interventions for the fracture, including surgical fixation with plates, it was later discovered that he had a bilateral os vesalianum pedis, which was identified as the source of his pain. This case emphasizes the importance of accurate diagnosis and management of accessory ossicles, particularly in young athletes, to avoid unnecessary treatments.