Fibulotalocalcaneal ligament: magnetic resonance imaging findings with cadaver correlation

The objectives of this study were to determine whether the fibulotalocalcaneal (FTC) ligament of the ankle, described in anatomical literature, can be identified on magnetic resonance (MR) imaging studies.

Magnetic resonance imaging was performed on 6 cadaver ankles, which were then sectioned axially. The posterolateral ankle was inspected on MR imaging and cadaver sections for ligamentous thickening corresponding to the components of the FTC ligament: main stem and talar and peroneocalcaneal laminae.

The entire FTC ligament or components of it were seen in 5 (83%) of 6 ankles. In 3 (50%) of 6, all 3 components were present. The main stem of the FTC ligament attached to the posteromedial aspect of the lateral malleolus and then divided inferiorly into 2 laminae: The talar lamina extended horizontally to the talus, and the peroneocalcaneal lamina descended vertically to the calcaneus.

The FTC ligament is a sheetlike extrinsic ligament, which is in continuity with the deep posterior crural fascia of the ankle and is visible on MR imaging.