Transverse tibiofibular ligament

At a glance

English

Transverse tibiofibular ligament

Latin (TA2)

Ligamentum tibiofibulare transversum

System

Ligament

Region

Foot

Side

Paired, left and right

About the transverse tibiofibular ligament

The transverse tibiofibular ligament, also called the inferior transverse ligament, is the deepest band at the back of the distal tibiofibular syndesmosis. It lies just in front of, and partly within, the posterior tibiofibular ligament. It is strong and thick, made of yellowish fibres, and runs crosswise behind the ankle joint. Its lateral end is fixed to the lateral malleolus, on the margin of the malleolar fossa, and its medial end reaches the back edge of the tibial articular surface, extending almost as far as the medial malleolus.

Its special feature is that it hangs slightly below the posterior margins of the tibia and fibula. In doing so it adds a fibrous lip to the back of the ankle mortise, and its smooth deep surface is covered by synovial membrane and touches the talus directly. It thus forms part of the articular surface for the back of the talar dome, much as a labrum deepens a socket. Just below it lies the posterior talofibular ligament, and the tendon of flexor hallucis longus runs behind the joint a little medially.

By deepening the mortise at the back, the ligament helps stop the talus sliding backwards out of the joint, especially when the foot is pointed down and the narrower posterior part of the talar dome sits in the socket. It also adds to the binding of the fibula to the tibia, so the two bones act together as a stable pair of jaws around the talus.

Injury usually forms part of a wider syndesmosis injury after external rotation of the foot. The ligament may also be a source of pain at the back of the ankle when thickened or trapped in posterior impingement, which is common in dancers and footballers.

Attachments and function

Attaches from

The lateral malleolus, at the margin of the malleolar fossa.

Attaches to

The back edge of the lower tibial joint surface, reaching nearly to the medial malleolus.

Function

Deepens the back of the ankle mortise, forms part of the articular surface for the talus, resists backward displacement of the talus and helps bind the fibula to the tibia.

Nerve supply

Articular branches of the tibial nerve.

Blood supply

Branches of the fibular (peroneal) artery and the posterior tibial artery.