Distal tibiofibular syndesmotic instability: revisiting essential concepts and clarifying advanced imaging tests

Most acute ankle sprains involve injuries to the lateral collateral ligaments, while a smaller proportion pertain to injuries of the deltoid ligament or the distal tibiofibular syndesmosis ligaments. Despite being less common, syndesmotic injuries can lead to persistent symptoms, extended recovery periods, and more intricate treatment protocols compared to lateral collateral ligament injuries. In the decision-making process for treating syndesmotic injuries, evaluating both ligament tears and the degree of joint instability is essential, as the latter determines whether a patient should be treated conservatively or surgically. Imaging has an established role in diagnosing syndesmotic ligament injuries; however, conventional imaging techniques have limitations in assessing instability. In this qualitative review, the authors discuss the anatomy and biomechanics, along with a review of current imaging techniques for evaluating syndesmotic instability. By clarifying imaging strategies, comparing diagnostic methods, and introducing emerging techniques, this review serves as a valuable resource for radiologists aiming to expand their knowledge of syndesmotic instability, particularly in cases that may be subtle and often missed on routine studies.