Fibulotalocalcaneal ligament: magnetic resonance imaging findings with cadaver correlation.

Objective: 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.
Methods: 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.
Results: 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.
Conclusions: 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.