PMC7682201_01
Initial radiographs after injury. (a) Distal AP and lateral radiographs showing a significant separation of the syndesmosis, widened medial joint space, intact distal fibula posterior displacement, and posterior dislocation of talus. (b) Oblique fibular fracture in the proximal third of the shaft.
10.1177_2050313X20974525-fig1.jpg
PMC7682201_01_10.1177_2050313X20974525-fig1.jpg
fig1-2050313X20974525
The lateral view of radiographs showed posterior displacement of the intact distal fibula with no fracture and posterior dislocation of the talus (Figure 1).
Preoperative CT and MRI images after manually closed reduction. (a) Posterior subluxation of talus and avulsed fractures of the posterior malleolus on the lateral view of CT scan. (b, c) Loose osteochondral fragments in the tibiotalar joint space on both the coronal and the sagittal views of CT scan. (d-f) Distal fibula posteriorly displaced from the normal tibial notch and fixed behind the posterolateral tibial tubercle, and avulsed fracture of the posterior malleolus on an axial view of CT and MRI images.
10.1177_2050313X20974525-fig2.jpg
PMC7682201_01_10.1177_2050313X20974525-fig2.jpg
fig2-2050313X20974525
Unexpectedly, multiple free osteochondral fragments were found between the distal tibial plafond and the talar dome, which were also observed in the subsequent MRI images (Figure 2).
Preoperative MRI images and a cured infectious wound on the anteromedial region of the ankle. (a) Posterior subluxation of the talus on a sagittal view of MRI. (b-d) Loose osteochondral fragments in the tibiotalar joint on both coronal and sagittal view of MRI, and the rupture of the deltoid ligament on coronal view of MRI. (e, f) A cured infectious wound on the anteromedial region of the ankle.
10.1177_2050313X20974525-fig3.jpg
PMC7682201_01_10.1177_2050313X20974525-fig3.jpg
fig3-2050313X20974525
In addition, MRI of the coronal plane revealed the rupture of the deltoid ligament (Figure 3).
Removal of loose osteochondral fragments in the tibiotalar joint and repair of the deltoid ligament. (a, b) Removal of loose osteochondral fragments with arthroscopy technique. (c, d) Preoperative ruptured and postoperative repaired deltoid ligament.
10.1177_2050313X20974525-fig4.jpg
PMC7682201_01_10.1177_2050313X20974525-fig4.jpg
fig4-2050313X20974525
The hematoma and several osteochondral loose fragments (size ~0.5 to 1 cm2) located in the middle and medial side of the posterior tibiotalar space were smoothly removed after the ankle plantar flexion (Figure 4). Finally, two anchor sutures were inserted into the tip of the medial malleolus to repair the torn deltoid ligament (Figure 4).
Postoperative images showing the satisfactory position of the injured ankle. (a, b) Postoperative radiographs showing full reduction of the distal dislocated fibula and near anatomical joint space of the ankle. (c, d) Satisfactory tibiotalar joint space on both coronal and sagittal views of CT scan. (e) Full reduction of the syndesmosis on an axial view of CT scan. (f, g) Postoperative 3D reconstructions of CT showing the syndesmosis fixation with two quadricortical lag screws and the nearly normal ankle joint position.
10.1177_2050313X20974525-fig5.jpg
PMC7682201_01_10.1177_2050313X20974525-fig5.jpg
fig5-2050313X20974525
Postoperative images of X-ray and CT also showed acceptable position of the injured ankle (Figure 5).
Patient showed good imaging appearances and a satisfactory clinical outcome after removing the hardware, 15 weeks after surgery. (a, b) Radiographs on AP and lateral view showing the normal position of the ankle. (c) Continuous appearance of the deltoid ligament on the coronal view of ankle MRI. (d, e) Tibiotalar joint and syndesmosis on sagittal and axial views of MRI. (f) Pain-free range of motion of the ankle with active dorsiflexion and plantar flexion.
10.1177_2050313X20974525-fig6.jpg
PMC7682201_01_10.1177_2050313X20974525-fig6.jpg
fig6-2050313X20974525
Three months after surgery, the syndesmosis screw was removed, and the subsequent images of X-ray and MRI showed a satisfactory position of the ankle joint and the continuous deltoid ligament (Figure 6).
Satisfactory radiographic and clinical outcome, 26 weeks after surgery. (a, b) Radiographs on AP and lateral view showing the normal position of the ankle. (c, d) Radiographic bone union of proximal fibular fracture. (e, f) Active dorsiflexion and plantar flexion of bilateral ankle joint.
10.1177_2050313X20974525-fig7.jpg
PMC7682201_01_10.1177_2050313X20974525-fig7.jpg
fig7-2050313X20974525
At the last follow-up of 6 months, the patient recovered well and obtained a pain-free range of motion of the ankle with passive 10  dorsiflexion and 40  plantar flexion (Figure 7), and luckily resumed her normal gait and daily activities.