Learning objectives
Recognize the normal bone structure of the foot with emphasis on sesamoids and accessory ossicles;
Recognize their presence,
prevalence and morphological variations;
Radiography,
CT and MRI of the normal anatomy and pathology of these bones.
Background
Sesamoids and accessory ossicles of the foot vary widely in their prevalence and morphology.
There are almost 40 acessory ossicles described and the more common ones are: os peroneum; os subfibulare; os subtibiale; os tibiale externum; os trigonum; os calcaneus secundaris; os intermetatarseum; os supratalare; os supranaviculare and bipartite hallux sesamoid.
Sesamoid bones are generally thought to form from a combination of biological and mechanical factors,
beginning as cartilaginous nodules that then undergo endochondral ossification during early to late childhood.
Accessory bones are supernumerary bones...
Imaging findings OR Procedure Details
Accessory and sesamoid bones are normal structures of the foot that in normal conditions are asymptomatic.
They are generally small,
well-corticated and ovoid bones.
Sesamoid bones may be bipartite or multipartite,
and are located close to a bone or a joint.
Awareness of the presence of sesamoids and accessory bones is helpful to not misdiagnose them as fractures.
Although rare,
symptomatic accessory and sesamoid bones may be associated with painful syndromes,
due to various pathologies,
including trauma,
infection,
inflammation and degeneration.
Sesamoid Bones
Sesamoids are...
Conclusion
Awareness of the location,
imaging characteristics,
and associated pathologic entities is important for accurate image interpretation of alterations affecting accessory ossicles and sesamoid bones.
References
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Coskun...