Ankle Joint Anatomy PDF

ANKLE JOINT  ANKLE JOINT ❖ Retinacula in the ankle prevent bow stringing of tendons ❖ Three bones involved – the tibia, fibula and the talus ❖ The tibia articulates superiorly and medially whilst the fibula articulates laterally ❖ Th...

ANKLE JOINT  ANKLE JOINT ❖ Retinacula in the ankle prevent bow stringing of tendons ❖ Three bones involved – the tibia, fibula and the talus ❖ The tibia articulates superiorly and medially whilst the fibula articulates laterally ❖ The talus provides the inferior articulatory surface ❖ Malleoli are landmarks in the distal superficial venous drainage of the lower limb  ARTICULATIONS OF THE TIBIA AND FIBULA ❖ 3 articulations a) Proximal – the tibio-fibular articulation – planar type of synovial joint b) Intermediate – interosseous membrane, syndesmoses c) Distal – tibio-fibular syndesmosis (fibrous joint) the joint is held together by two ligaments, the anterior and posterior distal tibio/fibularligaments which form a syndesmosis. This stabilizes the joint; this joint is further strengthened by a transverse tibio-fibular ligament. The distal tibio fibular ligament increases articulation  THE ANKLE JOINT ❖ The ankle is a hinge synovial joint classically known as a GINGLYMUS ❖ It is a rolling hinge joint and the plane of rotation allows both dorsiflexion and plantar flexion  LIGAMENTS OF THE ANKLE Deltoid ligament supports the medial side of the joint, attaches to the medial malleolus and insert into calcaneus, navicular tuberosity. This is the strongest ligament as it has both a superficial and deep component. It has anterior, middle and posterior fibres. It is crossed by the tendons of tibialis posterior an flexor digitorum longus which reinforce the ligament  LIGAMENTS OF THE ANKLE Anterior and posterior talofibular ligaments support the lateral side of the joint from the lateral malleolus of the fibula to the dorsal and ventral ends of the talus. Together these are the lateral ligaments of the ankle joint Calcaneofibular ligament is attached at the lateral malleolus and to the lateral surface of the calcaneus  OSTEOLOGY 7 tarsals, each have 6 surfaces Calcaneus Talus: Have a head, neck and body. Its dorsal surface (also known as the trochlear) is concave with a medial and lateral crest at each edge. It is wider in front than behind. The talus articulates with the calcaneus to form talo-cacaneal joints also known as sub talar joints. It is a uniaxial hinge joint. The talus and calcaneus articulate at 2 pointsthe anterior talocalcaneal articulation and the posterior talocalcaneal articulation; these articulations are separated by a deep groove which runs antero laterally, the tarsal canal. The subtalar joint allows side to side motion of the foot (inversion and eversion) and form the 3 part sub talor joint. They allow us to walk on sloping or uneven ground, it allows 30o of inversion and 15o of eversion  OSTEOLOGY Navicular Cuboid Medial intermediate and lateral cuneiforms 5 metatarsals 14 phalanges  ARCHES OF THE FOOT ❖ 3 arches, present at birth ❖ 2 main arches run antero posteriorly Media longitudinal arch Lateral longitudinal arch ❖ 1 transverse arch  ANKLE MOVEMENT ❖ Dorsiflexion The broader anterior portion of the trochlea of the talus occupies the whole mortise of the joint achieving maximal stability. The tibiofibular syndesmoses tightens heightening stability during dorsiflexion Muscles supplied by the fibular portion of the sciatic nerve ❖ Plantar flexion Narrow part of the trochlea occupies the mortise, it I least stable during plantar flexion Muscles are supplied by the tibial portion of the sciatic nerve  INJURIES ❖ Dislocation of the joint during landing ❖ Fracture, usually a fracture involves damage on both the medial and lateral aspects of the joint, this is because the angle is a ring of bones and ligaments ❖ Pott’s fracture excessive eversion causes combined abduction and external rotation, this cracks the medial malleolus and lateral malleolus due to pulling on the strong medial deltoid ligament