Transverse tibiofibular ligament

The transverse tibiofibular ligament (Inferior transverse tibiofibular ligament; Intermalleolar ligament) is located at the distal tibiofibular syndesmosis, forming part of the posterior aspect of the ankle joint. It originates just below the posterior tibiofibular ligament and extends transversely from the posterior edge of the tibia to the posterior margin of the lateral malleolus of the fibula. This ligament is variably present, with anatomical studies identifying it in approximately 70% of specimens, and its dimensions and shape can vary depending on the attachment points.

Functionally, the inferior transverse tibiofibular ligament reinforces the posterior capsule of the ankle joint and contributes to the stability of the tibiofibular mortise, particularly in resisting posterior translation of the talus.

For some authors, it is considered a part of the posterior tibiofibular ligament and some anatomical literature notes that the term "inferior transverse ligament" has historically been used interchangeably with the intermalleolar ligament, though current consensus distinguishes it as the inferior portion of the posterior tibiofibular ligament.