Multiple Calcaneus Secundarius Ossicles Presenting with Anterior Foot Pain: A Case Report Highlighting Characteristic Imaging Features.

Background

Calcaneus secundarius (CS) is an accessory ossicle located at the anterior aspect of the calcaneus and is typically an incidental and asymptomatic radiographic finding. However, it may become symptomatic following trauma or repetitive mechanical stress and can mimic anterior calcaneal process fracture or tarsal coalition, leading to diagnostic confusion. The presence of multiple independent CS ossicles represents a rare morphological variant and a potential source of diagnostic ambiguity.

Methods

We report the case of a 19-year-old male soldier who presented with progressive anterior foot pain following soccer activity without a clearly identifiable traumatic event. Radiographs, computed tomography (CT), and magnetic resonance imaging (MRI) were performed to evaluate the underlying pathology.

Results

CT demonstrated two separate, well-corticated accessory ossicles adjacent to the anterior calcaneal process without bony continuity. MRI revealed focal bone marrow edema (BME) at the calcaneus-ossicle interface, suggesting mechanical irritation at the fibrous connection. Due to persistent symptoms and concordant imaging findings, surgical excision was performed, resulting in immediate pain relief and return to full daily and sports activities without recurrence at the 1-year follow-up.

Conclusions

Multiple CS ossicles may produce fragment-like imaging appearances and increase the risk of misdiagnosis. Recognition of characteristic imaging features, particularly well-corticated ossicles and focal BME at the ossicle-calcaneus interface, together with clinical correlation, is essential for accurate diagnosis and appropriate management in patients with persistent anterior foot pain.