Ankle & foot joints

Ankle Joint (talocrural joint)

synovial joint | modified hinge | articular surfaces are covered with hylaine cartilage
weight bearing surfaces
- upper facet of talus
- inferior facet of tibia
capsule
- attached to the articular margins of fibula, tibia and talus (except for anterior part of talus - were it is fixed to neck, some distance from articular margin)
ligmanents
- Medial
  - Deltoid
    - 2 layers
      - Deep part
        
        narrow band extending from medial malleolus to side of talus
      - Superficial part
        
        triangular in shape
        
        apex: medial malleolus
        
        base: medial tubercle of talus, sustentaculum tali, spring ligament, tuberosity of navicular
- Lateral
  - Anterior talofibular ligament
    - anterior border of lateral malleolus to neck of talus
  - Calcaneofibular ligament
    - tip of malleolus to lateral surface of calcaneus
  - Posterior tibiofibular ligament
    - lies horizontally
    - from malleolus to lateral tubercle of talus
Blood supply of capsule and ligaments
- anterior and posterior tibial arteries
- peroneal artery
Nerve supply of capsule and ligaments
- deep peroneal and tibial nerves

axis of rotation
- no fixed but changes between the extremems of PF and DF
- direction of axis is downwards and lateral
  - lateral surface of talus
  - medial surface of talus (at higher level)
Talus
- concave from side to side
- convex anteroposteriorly
- broad in front
- narrow behind
In dorsiflexion
- broad anterior articular area of talus is grasped by malleoli and tibia
- lateral rotation of fibular occurs
- 10 degrees
- muscles
  - tibialis anterior, long toe extensors, peroneus tertius
In plantarflexion
- smallest area of talus is in contact
- no inversion or eversion is possible in ankle joint
- 20 degrees
- muscles
  - gastrocnemius, solues, long flexor tendons, long and short peronei

Talocalcaneonavicular joint
- synovial joint | ball and socket
  - ball: head of talus
  - socket: navicular, calcaneus, spring ligament