PMC5559932_01
The appearance of the ankles before surgery. The anterolateral area of the right ankle was swollen and had an overlying callus. A callus may also be seen in the same position in the left foot.
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fig1
Physical examination revealed a fluctuant mass 5 x 8 cm in size, over the anterolateral part of the right ankle (Figure 1).
(a) Varus stress view of the ankle showing the talar tilt of 15 degrees. (b) Anterior drawer stress view of the ankle showing marked anterior displacement of the talus.
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fig2
Varus and anterior instability were obvious with stress radiography (Figure 2).
Magnetic resonance imaging of the right ankle. (a) An axial short T1 inversion recovery (STIR) image showing fluid collection in the lateral premalleolar bursa (asterisk). Fluid collection may also be seen in the tendon sheath of the extensor digitorum longus (EDL) (arrowhead). The anterior talofibular ligament is unstrained (arrow). (b) A sagittal STIR image showing fluid collection in the tendon sheath of the EDL just anterior to the ankle joint.
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fig3
MRI also showed unstrained ATFL and fluid collection in the sheath of the extensor digitorum longus (EDL) tendon (Figure 3).
Arthrogram of the right ankle. Constant medium leaked anteriorly into the syndesmosis and the tendon sheath of the extensor digitorum longus (asterisk). Leakage may also be seen in the tendon sheaths of the tibialis posterior (arrow) and the flexor hallucis longus (arrowhead).
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fig4
The arthrogram showed contrast medium leaking from the anterior aspect of the joint into the tendon sheath of the EDL and the distal tibiofibular syndesmosis and from the posterior aspect of the joint into the tendon sheath of the flexor hallucis longus (FHL) and the tibialis posterior indicating ruptures of the joint capsule of the ankle joint (Figure 4).
An intraoperative photograph of the resected bursa. The bursal cavity was in communication with the tendon sheath of the extensor digitorum longus (asterisks).
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fig5
When the underside surface of the bursa was being dissected from the underlying extensor retinaculum, the bursa was found to communicate with the tendon sheath of the EDL through a fistula 5 mm in diameter (Figure 5).