case_images: PMC8261161_01
case_images: Lateral radiograph of right ankle showing an os trigonum and posterior talus process fracture.
case_images: CRIOR2021-6637081.001.jpg
case_images: PMC8261161_01_CRIOR2021-6637081.001.jpg
case_images: fig1
case_images: The plain radiograph of the ankle demonstrated an os trigonum; however, due to the orientation of the medial tubercle, this was not clearly seen and he was incorrectly diagnosed as having os trigonum syndrome (see Figure 1).
case_images: Sagittal slice of T2 MRI of right ankle showing the posteromedial talus fracture fragment and associated oedema.
case_images: CRIOR2021-6637081.002.jpg
case_images: PMC8261161_01_CRIOR2021-6637081.002.jpg
case_images: fig2
case_images: The MRI scan reported mild inflammation associated with the os trigonum but also confirmed the presence of bone fragments posteromedially between FHL and the flexor digitorum longus (FDL) with marrow oedema affecting the medial tubercle of the talus (see Figure 2).
case_images: PMC8261161_02
case_images: Axial slice of T2 MRI of right ankle demonstrating fluid enhancement around the FHL tendon with the adjacent fractured posteromedial talus fragment.
case_images: CRIOR2021-6637081.003.jpg
case_images: PMC8261161_02_CRIOR2021-6637081.003.jpg
case_images: fig3
case_images: The fragment was between FDL and FHL tendons representing an "unusually located os trigonum," and there was also associated FHL tenosynovitis (see Figure 3).
case_images: Intraoperative image intensifier imaging demonstrating pre- (left) and post- (right) excision of the posteromedial talus fragment.
case_images: CRIOR2021-6637081.004.jpg
case_images: PMC8261161_02_CRIOR2021-6637081.004.jpg
case_images: fig4
case_images: He underwent operative intervention with an open excision of the bony fragment (see Figure 4).
case_images: PMC8261161_03
case_images: Lateral radiograph of right ankle demonstrating a prominent fractured and displaced posterior process of talus.
case_images: CRIOR2021-6637081.005.jpg
case_images: PMC8261161_03_CRIOR2021-6637081.005.jpg
case_images: fig5
case_images: His pain film radiograph demonstrated a prominent posterior process of the talus that was fractured and displaced, but this had been misdiagnosed as an os trigonum (see Figure 5).
case_images: Coronal slice of T2 MRI demonstrating the large os trigonum lateral to the FHL tendon and the fracture fragment medial to the FHL tendon.
case_images: CRIOR2021-6637081.006.jpg
case_images: PMC8261161_03_CRIOR2021-6637081.006.jpg
case_images: fig6
case_images: Interestingly, the MRI report did not describe the posteromedial tubercle fracture fragment that was the palpable mass (see Figure 6).
case_images: PMC8261161_04
case_images: Axial CT slice demonstrating lateral os trigonum and posteromedial talus fracture fragment nonunion.
case_images: CRIOR2021-6637081.007.jpg
case_images: PMC8261161_04_CRIOR2021-6637081.007.jpg
case_images: fig7
case_images: A right ankle CT scan demonstrated a malunion/partial union of the medial margin of the talus and secondary degenerative changes (see Figure 7).