Ankle Joint.pptx

Ankle joint

1. Ankle Joint Dr Abayomi T.A Department of Anatomy UNIOSUN

2. The  ankle joint  (or talocrural joint) is a synovial joint located in the lower limb. It is formed by the bones of the leg (tibia and fibula) and the foot (talus ). It is a complex hinge joint. Its main action is to allow dorsiflexion and plantar flexion of the foot

3. Articular surfaces In the ankle joint, articulations exist between the distal ends of the tibia and its medial malleolus, lateral malleolus of the fibula, and the trochlear surface of the talus The distal end of the tibia articulates with the trochlea of the talus The  medial malleolus articulates with the medial surface of the talus . The lateral malleolus of the fibula articulates with the lateral aspect of the talus . All articular surfaces are covered with hyaline cartilage

4. Ligaments There are two main sets of ligaments, which originate from each malleolus . Medial collateral ligament Lateral collateral ligament

5. Medial Collateral Ligament The medial collateral (deltoid) ligament is a strong, triangular band that reinforces the medial aspect of the ankle joint. It has a proximal attachment on the medial malleolus. and inserts onto the talus, calcaneus, and  navicular bones. It consists of 3 bands of ligaments based on its distal attachments Tibionavicular : composes the superficial fibers of the medial collateral ligament that descend from the medial malleolus to attach distally on the navicular tuberosity. Tibiocalcaneal : composes the intermediate part of the medial collateral ligament that passes from the medial malleolus to attach onto the sustentaculum tali . Tibiotalar : comprises the deep part of the medial collateral ligament. It consists of an anterior and posterior portion.  The anterior tibiotalar ligament descends to attach onto the medial tubercle of the talus, while the posterior tibiotalar ligament attaches onto the non-articular posterior part of the medial talar surface.

6. Lateral collateral ligament reinforces the lateral aspect of the ankle joint. It is comprised of three distinct bands : Anterior talofibular  – spans between the lateral malleolus and lateral aspect of the talus. Posterior talofibular  – spans between the lateral malleolus and the posterior aspect of the talus. Calcaneofibular  – spans between the lateral malleolus and the lateral aspect of calcaneus .

7. Movements/Muscles involved in ankle joint The ankle joint is a  hinge type joint , with movement permitted in one plane. Plantarflexion and dorsiflexion are the main movements that occur at the ankle joint. Eversion and inversion are produced at the other joints of the foot, such as the   subtalar joint . Plantarflexion  – produced by the muscles in the posterior compartment of the leg (gastrocnemius, soleus, plantaris and posterior tibialis ). Dorsiflexion  – produced by the muscles in the anterior compartment of the leg ( tibialis anterior, extensor hallucis longus and extensor digitorum longus ). Inversion of the ankle is produced by the main dorsiflexor of the foot, the tibialis anterior, as well as tibialis posterior, that acts as a plantar flexor. Eversion of the foot is produced by the dorsiflexor fibularis tertius , and plantar flexors fibularis longus and fibularis brevis .

8. Neurovascular Supply Innervation The ankle joint is innervated by the deep fibular ( peroneal ) nerve, the   tibial  and  sural nerves Blood supply The  arterial supply  to the ankle joint is derived from the malleolar branches of the anterior tibial , posterior tibial and fibular arteries. Venous blood is drained through the corresponding veins.

9. Clinical correlates Ankle sprain refers to partial or complete tears in the ligaments of the ankle joint. It usually occurs via excessive inversion to a plantarflexed and weight-bearing foot . Pott’s fracture is a term used to describe a  bimalleolar  (medial and lateral malleoli) or  trimalleolar  (medial and lateral malleoli, and distal tibia) fracture. This type of injury is produced by forced eversion of the foot.