Accessory ossicles and sesamoid bones of the ankle and foot: imaging findings, clinical significance and differential diagnosis

Abstract

Accessory ossicles and sesamoid bones are frequent findings in routine radiographs of the ankle and foot. They are commonly considered fortuitous and unrelated to the patient's complaint; however, they may eventually cause painful syndromes or degenerative changes in response to overuse and trauma. They may also suffer or simulate fractures. Our aim was to review, illustrate and discuss the imaging findings of some of the more frequent accessory ossicles and sesamoid bones of the ankle and foot region, with particular emphasis on those that may be of clinical significance or simulate fractures.

Clinical Meaning of Hot Uptake on Bone Scan in Symptomatic Accessory Navicular Bones

“…It is also called the os tibiale externum, prehallux, or navicular secondum [2]. It is relatively common and reported to be present in 4-21 % of the population [3][4][5][6]. Usually, it is asymptomatic and observed incidentally.…”

“…The mechanism of pain might be due to overuse or traumatic or degenerative changes at the synchondrosis, or to inflammation related to fusion and the bony prominence [3,8]. A chronic stress reaction has been suggested based on pathologic reports about micro-fractures, new bone formation and inflammation, and cellular proliferation through the cartilaginous synchondrosis [9].…”

“…A chronic stress reaction has been suggested based on pathologic reports about micro-fractures, new bone formation and inflammation, and cellular proliferation through the cartilaginous synchondrosis [9]. There is also osteonecrosis, which creates bone marrow edema on magnetic resonance imaging [3]. Usually, the first line treatment is conservative [1].…”

Os Subfibulare: A case report of painful fibular accessory ossicle

“…Accessory bones that are rare in the foot include accessory interphalangeus, os peroneum, anamolous os calcaneum and talus, os trignum and os tibiale extenum. [1][2][3][4][5][6] Os peroneum can fracture following an inversion and may mimic sport injury. 7 An accessory, distal focus of epiphyseal ossification may develop in either malleolus.…”

A rare case of symptomatic os supranaviculare in a sportsman

“…The os supranaviculare may fuse with the navicular to form a spur of no clinical significance 3 . Symptomatic os supranaviculare may be misdiagnosed as the cortical avulsion fracture of the navicular bone or talar head 1 . Clinical examination, pain localization, mechanism of injury or overuse along with radiological investigations were helpful for correct diagnosis.…”