12 The surface of the talus forms an arched deepening from ventral to dorsal direction, ensuring a rotational stability in dorsoplantar movements. In the frontal plane, the trochlea of the talus shows a lateral slope of about nine degrees. The convex-shaped talus has a greater articular surface than the corresponding concave-shaped facies articularis inferior of the tibia ( Fig. 5, 12 In the sagittal plane, there also exists an incongruity between the articular surface of the talus and the distal tibia. 3 On the medial side, the articulation between talus and malleolus shows a larger contact surface. 11 Looking from above at the trochlea tali, it is wedge-shaped with a broader anterior portion. 10 The shape of the talus is complex, resulting in a changing axis of rotation. Over half of the surface of the talus is covered with cartilage without any tendon insertions. 2 Via the syndesmotic complex, the fibula is dynamically fixed to the tibia ( Fig. 8 Due to the length of the fibula, the articular portion reaches further in distal direction in comparison to the medial malleolus. (D) Oblique magnetic resonance image at the level of the tibiotalar joint with distal anterior tibiofibular ligament (ATIFL) (3) and the distal posterior tibiofibular ligament (PTIFL) (4).įurthermore, the fibula is connected with the corresponding articular surface of the talus. The incisura tibialis is formed by the anterior (Chaput’s tubercle) (1) and posterior tubercle (2) of the tibia. The concave-shaped incisura tibialis (filled arrowhead) matches the convex shape of the fibula. (C) Axial computerized tomography (CT) image at the level of the distal tibiofibular. The tibia is concave-shaped in the sagittal plane and the arc length of the talus with around 120° is greater in comparison to the tibia with its 80°. (B) Lateral radiograph of the ankle of the same patient of (A). Regarding the length of the fibula, the articular portion reaches further in distal direction in comparison to the medial malleolus. (A) Ankle anteroposterior (AP) mortise view of a healthy young male showing the configuration between distal tibia, distal fibula and talus. The contact zone between tibia and fibula is covered by a thin layer of cartilage forming the syndesmotic recess. Likewise, the anterior (Le Fort-Wagstaffe tubercle) and posterior tubercle of the fibula form a convex triangle. The incisura tibialis is formed by the anterior (Chaput’s tubercle) and posterior tubercle of the tibia ( Fig. The concave-shaped incisura tibialis matches the convex shape of the fibula ( Fig. 4– 6 Besides the connection between tibia and talus, there exists a close interaction between tibia and fibula. Considering the bone mineral density of the tibia, the articular site shows a higher density in comparison to the metaphysis. Looking at the coronal plane, the tibia shows a slight slope from medial to lateral and is concave-shaped in the sagittal plane ( Fig. 2, 3įrom the tibia, the facies articularis medialis (pilon) and the facies articularis inferior are connected to the talus. Tibia, fibula and talus are interconnected through collateral ligaments and the syndesmotic ligament complex.
1 The talocrural (TC) joint is formed by three bones and a complex ligamentous apparatus. The human ankle joint complex can be divided in a talocrural, a talocalcaneonavicular and a subtalar part.
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