Presentation
Pain after football injury. X-ray ? navicular fracture.
Patient Data
Age: 20 years
Gender: Male
From the case:
Os calcaneus secundarius
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No fracture identified. Incidental accessory navicular bone and os calcaneus secundarius. Alignment is normal.
From the case:
Os calcaneus secundarius
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There is a possible undisplaced transverse fracture through the medial aspect of the navicular on the AP projection which represents a typical type II os tibiale externum and not a fracture, as the margins are smooth and well-corticated, as well as in a typical location for this ossicle. This is what led to the CT.
Case Discussion
This ossicle can simulate an intra-articular fracture.