The Ankle Flashcards
Name the arteries that supply the foot and state where pulses can be located
Dorsalis pedis - just lateral to Extensor hallucis longus tendon
Posterior tibial
Describe eversion and inversion of the foot
Eversion - lateral part of foot rolls out, moves away from ground, foot rolls in
Inversion - lateral part of foot rolls in, moves towards/into ground, foot rolls out
What classification of joint is the ankle ?
Rolling (axis of rotation not fixed) hinge synovial joint
Name the 7 tarsal bones of the foot.
Talus Calcaneus Navicular Cuboid Cuneiforms (medial, intermediate, lateral)
During dorsiflexion, which part of the talus is within the mortise of the ankle joint?
Anterior part
Why is the ankle more stable during dorsiflexion?
Wider, wedge shaped anterior part of talus is in the mortise
What type of articular cartilage is present in the ankle joint?
List some properties: *ToB
Cell type/s present
Fibre type/s present
Hyaline
Chondrocytes
Type II collagen
*ToB
What are the components of cartilage extra cellular matrix?
Proteoglycans (containing glycoaminoglycans) Hyaluronic acid (another GAG)
What is the specific name of the type of joint the ankle is?
Give overall description of the structure.
Mortise and tendon, Bracket shape formed by tib & fib into which talus bone fits and articulates.
What is the function of the various retinacula of the ankle?
Prevent bow stringing of tendons - allow function of muscles
What are the 2 sets of ligaments in the ankle and where do they originate from?
Medial (deltoid) and lateral ligaments
Malleoli
Describe the parts of the medial (deltoid) ligament
Superficial and deep Fan out downwards from medial malleolus 3 superficial : Tibio-navicular ligament* Calcaneotibial ligament Talo-tibial ligament Deep: Related to the superficial tibio-navicular ligament
What is the primary function of the medial ligament of the ankle?
Resist eversion of the foot.
Describe the parts of the lateral ligament
There are 3:
Anterior talofibular
Posterior talofibular
Calcaneofibular
Describe the ankle “ring” and state it’s clinical relevance.
Upper part - articular surfaces of tibia and fibula
Lower part - subtalar joint
Sides - medial and lateral ligaments
Ring usually breaks in 2 places
What movements occur at the ankle joint ?
State the muscles responsible in each case.
Dorsiflexion:
Tibialis anterior, Extensor hallucis longus, Extensor digitorum longus
Plantar flexion:
Gastrocnemius, Soleus, Posterior tibialis, Plantaris
What are the malleoli useful landmarks for ?
Medial malleolus - great saphenous vein also pulse from tibialis posterior artery
Lateral malleolus - small saphenous vein
What is a Pott’s fracture? And how do they occur (3 stages)?
Bimalleolar or trimalleolar (distal tibia involved) fracture of ankle
1. Forced eversion of foot pulls on medial ligaments -> avulsion fracture to medial malleolus
2. Talus moves laterally, breaking off lateral malleolus
3. Tibia forced anteriorly, shearing off distal and posterior part against the talus
(See saved picture/diagram)
What articular surfaces does the tibia contribute to the ankle?
Superior
Medial
What articular surface does fibula contribute to the ankle joint?
Lateral
What articulatory surfaces does the talus bone contribute to the ankle?
Inferior ( NB superior surface of talus)
Infero-medial
Infero-lateral
Describe the proximal articulation site of tibia and fibular
= Tibio-fibular articulation
Plane type synovial
Describe the intermediate articulation of tibia and fibular?
Interosseous membrane
Describe the distal articulation of tibia and fibular?
=Tibio-fibular syndesmosis
Fibrous joint made up of anterior posterior distal tibio/fibular ligaments
What does the distal posterior tibio-fibular ligament do?
Further strengthens ankle joint
Deepens articulatory surfaces
What are the sub-talar joints?
Articulations of talus and calcaneous
Not part of ankle joint proper
What are the joint stabilising surfaces of the ankle?
Medial and lateral malleoli
Distal tibio-fibular ligament (posteriorly)
Transverse tibio-fibular ligament
Describe the arches of the foot
Medial and lateral longitudinal arches
Transverse arch
What classification of joint is the talo-calcaneal joint?
Uni axial hinge
What movement does the subtalar joint allow?
Inversion and eversion of the foot
Side to side motion
What contributes to stability in the ankle in extreme dorsiflexion?
The tibio-fibular syndesmosis
When is the ankle least stable?
Plantar flexion
What nerve is responsible for dorsiflexion?
Fibular division of sciatic nerve (L4-5)
What nerve is responsible for plantar flexion ?
Tibial division of the sciatic nerve (L4-5)
What is the strongest ligament of the ankle joint?
Medial (deltoid) ligament of ankle joint
