Proximally to the ankle joint, in the distal portions of the fibula and tibia, we find an important joint: the distal tibio-fibular joint (syndesmosis). It is formed by the rough convex surface of the medial surface of the distal end of the fibula and a rough concave surface of the lateral surface of the tibia. This joint is formed by the anterior and posterior tibio-fibular ligaments, inferior transverse and interosseous ligaments.

Anterior Tibio-fibular Ligament & #8211; It is a flat fiber bundle that extends obliquely, distally and laterally between the adjacent edges of the tibia and fibula, on the anterior face of syndesmosis.

Posterior Tibio-fibular Ligament & #8211; Smaller than the anterior, it is similarly arranged on the posterior face of syndesmosis.

Lower Transverse Ligament & #8211; It is anterior to the posterior ligament, and is a thick and robust bundle of yellowish fibers that run transversely from the lateral malleolus to the posterior edge of the articular face of the tibia.

Interosseous Ligament & #8211; It consists of numerous short, sturdy fibrous bundles that pass between the continuous rough surface of the tibia and fibula and form the main joining link between the bones.

The ankle joint itself is a tingle (hinge) formed by the distal end of the tibia and fibula. inferior transverse ligament and the talus.

The bones are connected by the joint capsule and the following ligaments: deltoid, anterior talofibular, posterior talofibular and calcaneofibular.

Articular Capsule & #8211; Cover the joint. The anterior part of the capsule is a wide thin membrane layer. The back of the capsule is very thin and formed mainly of transverse fibers.

Ligament Deltoid & #8211; It is a triangular beam, robust and flat. It consists of two fiber bundles: superficial (posterior tibionavicular, calcaneotibial and talotibial fibers) and deep (anterior talotibial fibers). Its main function is to stabilize the medial ankle region and prevent eversion movement.

  • Tibionavicular Fibers & #8211; They are inserted into the posterior tuberosity of the navicular bone and they join with the medial margin of the plantar calcaneonavicular ligament.
  • Calcaneotibial Fibers & #8211; They descend almost perpendicularly to fit the full length of the calcaneal stem support.
  • Posterior Talotibial Fibers & #8211; They move laterally to insert into the inner side of the stalk and the prominent tubercle on its posterior face, medial to the groove to the long flexor tendon of the hallux.
  • Anterior Talotibial Fibers & #8211; They are inserted into the tip of the medial malleolus and the medial face of the stalk.

Anterior Talofibular Ligament & #8211; It extends anteriorly and medially from the anterior margin of the fibular malleolus to the stalk, anteriorly to its lateral articular facet.

Posterior Talofibular Ligament & #8211; It runs almost horizontally from the depression in the medial and posterior part of the fibular malleolus to a prominent tubercle on the posterior aspect of the stalk, immediately lateral to the groove to the hallucis longus flexor tendon.

Calcaneofibular Ligament & #8211; It is a narrow, rounded cord that runs from the apex of the fibular malleolus to a tuber on the lateral surface of the calcaneus.

The three ligaments described above are collaterally referred to as Lateral Collateral Ligament. It supports the lateral aspect of the ankle, preventing inversion movement.

The Anterior Ligament and Calcaneofibularis are the most frequently injured in inversion of the ankle sprains. This is because with the foot in plantar flexion, the talus is more unstable in the ankle fitting, and therefore more dependent on the ligament support.

Distally to the joints studied above, we also find the intertarsal, tarsometatarsal, intermetatarsal, metatarsophalangeal joints and finger joints.

 Medial View of Ankle Joint Structures
Source: NETTER, Frank H .. Atlas of Human Anatomy. 2 ed. Porto Alegre: Artmed, 2000.
 Side View of Ankle Joint Structures
Source: NETTER, Frank H .. Atlas of Human Anatomy. 2 ed. Porto Alegre: Artmed, 2000.



Synovial Joints