Migration of the Os Peroneum: an Enigmatic Phenomenon Explored Through Radiological Perspectives

The os peroneum is an accessory ossicle located along the lateral aspect of the cuboid bone. Its position can serve as an indicator of peroneus longus tendon (PLT) injury. Imaging studies including radiographs and MRI can help detect malposition of the os peroneum and progressive injuries to the PLT and its associated structures. We report a case of a woman with recurrent foot and ankle pain, demonstrating progressive retraction of the os peroneum, implying severe PLT injury which may have ultimately predisposed her to a traumatic fifth metatarsal base fracture. This case highlights the importance of scrutinizing the appearance and position of the os peroneum on radiographs.