Isolated Ankle Syndesmotic Rupture: A Case Report

This report describes a case of acute, isolated rupture of the ankle syndesmosis in a 36-year-old man with no significant past medical history, sustained after a fall from a skateboard with an external rotation mechanism of injury.Plain radiographs demonstrated widening of the medial ankle mortise and the distal tibiofibular joint without an associated fracture, findings consistent with syndesmotic instability.The patient underwent operative repair consisting of clamp-assisted reduction, neutralization plating of the distal fibula, and suture-button (TightRope) fixation of the syndesmosis, with an uncomplicated postoperative course.This case highlights the importance of maintaining a high index of clinical suspicion for syndesmosis injury in patients with an external rotation mechanism, even when initial radiographs show no fracture, since isolated syndesmotic ruptures are easily overlooked yet carry a meaningful risk of chronic instability and early post-traumatic arthritis if missed or inadequately treated.