5 - The Fibulotalocalcaneal Complex: A Well-known Enigma. a Cadaveric Study

Poster Board Number: 5
There are separate poster presentation times for odd and even posters.
Odd poster #s – first hour
Even poster #s – second hour

Abstract Body : The lateral collateral ligament (LCL) complex of the ankle is the most commonly sprained structure in the lower extremity. Previous studies propose a new model of the LCL that shows a relationship between the anterior talofibular ligament (ATFL) and the calcaneofibular ligament (CFL) through connecting arciform fibers resulting in a single, functional isometric structure: the fibulotalocalcaneal ligament complex (FTCL). This study describes the structure and characteristics of the FTCL. Layer by layer dissection of the lateral aspect of the ankle was performed on 16 cadaveric ankles. The characteristics of the ATFL, CFL and any connecting fibers were recorded. Two independent observers measured the defined ligaments in neutral, plantarflexion, and dorsiflexion. The ATFL was a double-bundle structure in all specimens. The length of the ATFL superior fascicle increased during plantarflexion by an average of 0.69 mm (p = 0.0028) and decreased during dorsiflexion by an average of 0.67 mm (p = 0.00098). The length of the ATFL inferior fascicle showed no statistical difference whether in neutral, dorsiflexion or plantarflexion. The CFL in all specimens was not statistically different between neutral and dorsiflexion but was an average of 1.01 mm shorter in plantarflexion (p = 0.0389). Arciform fibers connecting the ATFL and CFL were identified in all specimens except for one that was over-dissected. No consistent insertion site was appreciated between the inferior bundle of the ATFL and the CFL. In conclusion, the FTCL is a consistent structure in all the dissected specimens with arciform fibers serving as an intrinsic reinforcement of the subtalar joint. The inferior fascicle of the ATFL is a functional isometric structure while the superior fascicle is not. This study provides a comprehensive understanding of the LCL complex and the dynamics between its component structures. An appreciation of this interrelationship supports consideration of a functional restoration of the LCL.