Structure and Ligaments of the Calcaneocuboid Joint
The structural stability of the calcaneocuboid joint is further reinforced by multiple layers of ligamentous systems. The dorsal and lateral portions of the joint capsule are specifically strengthened by the dorsal calcaneocuboid ligament. Additionally, the stability of this joint is further enhanced by three specialized ligaments. Of particular note is the bifurcated ligament, a distinctive "Y"-shaped fibrous structure attached just superior to the dorsal surface of the calcaneocuboid joint on the calcaneus. This ligament anatomically divides into two primary fibrous bundles: the medial (calcaneonavicular) bundle, which contributes to the lateral stability of the talonavicular joint, and the lateral (calcaneocuboid) bundle, which traverses the dorsal surface of the calcaneocuboid joint, forming a key structural link between the calcaneus and the cuboid bone.
The plantar stability of the joint is firmly maintained by the long plantar ligament and the short plantar ligament. The long plantar ligament, the longest of the foot’s ligamentous structures, originates from the anterior rough surface of the calcaneus and extends along the plantar surface of the calcaneus. It ultimately attaches to the plantar surfaces of 3-4 metatarsal bones located laterally, forming an extensive support structure. Meanwhile, the short plantar ligament, also known as the plantar calcaneocuboid ligament, originates from the deep anterior aspect of the plantar surface of the calcaneus and attaches to the plantar surface of the cuboid bone. Although more localized, this ligament plays a crucial role in stabilization. Due to the unique vertical trajectory of these plantar ligaments as they cross the calcaneocuboid joint, the lateral column of the foot secures highly effective structural stability.