Case: A 37-year-old man presented after a sudden snap followed by pain in the medial side of the ankle while playing football. Physical examination showed edema and pain posteriorly to the medial malleolus, and a longitudinal structure was palpable anteriorly. Ultrasound confirmed a dislocated tibialis posterior tendon (TPT). The patient underwent surgery, and the flexor retinaculum was repaired. Six months after the surgery, he was asymptomatic and had resumed his usual physical activity, with an AOFAS score of 100.
Conclusion: TPT dislocation is rare and orthopaedic surgeons should be aware of this condition in patients with a sudden traumatic medial ankle pain.