1. lateral ligament, ankle There are two lateral ligaments of the ankle - internal and external. The internal lateral ligament is attached to the apex and anterior and posterior bodies of the inner malleolus and inserted into the navicular bone, the inferior calcaneo-navicular ligament, the sustentaculum tali of the os calcis, and the inner side of the astragalus. The externallateral ligament, also called the lateralcollateral ligament, consists of three distinct fasciculi - the calcaneofibular, the anterior talofibular, and the posterior talofibular.