Anterior inferior tibiofibular ligament (AITFL)

The anterior inferior tibiofibular ligament (AITFL) is part of the lateral collateral ligament complex of the ankle.

Gross anatomy

It generally has a trapezoidal shape, with multiple bands of fibers that extends obliquely in a distal and lateral direction from the tibia to the fibula. It usually becomes thicker from superior to inferior.

It starts from the distal tibia at around 5 mm above the articular surface and descends obliquely between the adjacent margins of the tibia and fibula, anterior to the syndesmosis to the anterior aspect of the lateral malleolus. Length ranges from 12-20 mm and thickness 1-3 mm.

Width range :

• 7-12 mm at the fibular insertion to
• 9-22 mm at the tibial insertion

Classification 

One classification method according to Ray and Kriz is as follows :

• type 1: multiple fascicles (more than three) with or without small gaps between adjacent fascicles
  • type 1a: inferior fascicle separated from the rest of the ligament by a gap and possesses its own distinct proximal and distal attachments
  • type 1b: inferior fascicle is not completely separated from the rest of the ligament by a gap; either its proximal or distal attachment is continuous with rest of the ligament
  • type 1c: multiple fascicles without gaps intervening between them
• type 2: three fascicles or less; distinct inferior fascicle with both its proximal and distal attachments separate from rest of the ligament; inferior fascicle separated completely from the main portion of the ligament by a gap
• type 3: three fascicles or less; distinct inferior fascicle with either its proximal or its distal attachment continuous with the rest of the ligament; gap does not completely separate the inferior fascicle from rest of the ligament
• type 4: three fascicles or less; lower portion of the ligament possesses an inferior fascicle with both its proximal and distal attachments for the rest of the ligament
• type 5: three fascicles or less; ligament with no separations or gaps within its structure and may or may not possess a fascicular arrangement

Variant anatomy 

• accessory anterior inferior tibiofibular ligament  / Bassett's ligament

Related pathology

• distal tibiofibular syndesmosis injury​

Siehe auch:

• Ruptur distale tibiofibulare Syndesmose
• Bassett's ligament