Anatomy of the lateral complex of the ankle joint in relation to peroneal tendons, distal fibula and talus: a cadaveric study.

OBJECTIVES: The anatomy of the lateral complex of the ankle joint comprises multiple ligaments and muscles. This study aims to demonstrate the complexity of the lateral ankle structures in detail. MATERIALS AND METHODS: The study was performed on 11 cadavers (22 ankles) fixed in 10% formaldehyde, and 24 free talus specimens. The detailed course and attachments of each ligament was observed and noted with the ankle in neutral position. Talar measurements were applied to 46 specimens including the dissected cadavers and free talus ones. This study also investigated the relationships between these ligaments and gross morphologic pattern of lateral complex and talus, including the morphological pattern of the peroneal groove and the relationship between the peroneal tendons before and after the peroneal groove. RESULTS: The whole relationship of lateral ankle structures including anatomic and morphologic patterns and talus were evaluated. No morphologic variation was found concerning peroneus brevis and longus muscles. Although the existence of peroneus quartus muscle has been reported to be 6.6%, we detected it in two of our dissections (9%). We found a peroneus quinti in four of our dissections. We also found an extraordinary ligamentous structure that runs between the distal lateral process of the calcaneus and the inferior peroneal retinaculum in 12 of our dissections. A single form of the anterior talofibular ligament (ATFL) was observed in 23%, a bifurcate ATFL in 59% and the trifurcate ATFL in 18% of the dissected ankles in this study. CONCLUSION: Understanding the detailed anatomy of lateral ligament complex of the ankle joint with their relationships to the osseous structures and biomechanics of the ankle can help increase the success of treatment on ankle pathologies.