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Flashcards in The ankle joint Deck (28):

What type of joint is the ankle joint? (name both)

synovial joint
hinge type joint (movement)


Which bones form the ankle joint?

tibia, fibula & talus


What movements does the ankle joint allow? why?

dorsiflexion & plantarflexion of the foot
as it is a hinge joint


What binds the tibia & fibula together?

tibiofibular ligaments


What does the tibiofibular joint form?

a bracket shaped socket for the talus called mortise


What shape is the articulating part of the talus with the tibia & fibula? How does this shape help?

wedge shape: wider anterior, thinner posterior
helps stable the joint during dorsiflexion (anterior part held in mortise)


Where do the ligaments for the ankle joint originate from?

each malleolus (medial & lateral)


Which ligament attaches to the medial malleolus?

medial ligament (or deltoid ligament)


What does the medial malleolus consist of? Where does it attach to?

medial malleolus consists of 4 separate ligaments
all fan out from medial malleolus
attaches to talus, calcaneus & navicular bones


What is the primary action of the medial ligament?

prevents over-eversion of the foot


What originates from the lateral ligament?

lateral malleolus


What does the lateral ligament prevent?

over inversion of the foot


What is the lateral made up of?

3 distinct & separate ligaments


Name the 3 ligaments of the lateral ligament and where they are found

1. anterior talofibular: between lateral malleolus & lateral aspect of talus
2. posterior talofibular: between lateral malleolus & posterior aspect of talus
3. calcaneofibular: between lateral malleolus & calcaneus


What is the ankle joint also known as?

talocrural joint


Clinical: what is the ankle 'ring'?

the ankle joint & associated ligaments can be visualised as a ring in the coronal plane (frontal plane - belly & back)


Name the components of the ankle 'ring'

upper part: articulating sides of tibia & fibula
lower part: subtalar joint (between talus & calcaneous)
sides: medial & lateral ligaments


What is significant about a fracture to the ankle 'ring'?

it normally breaks in 2 places (like a polo mint)
can occur with ligament damage - wouldn't show up on x-ray


Where is inversion & eversion of the ankle produced?

at the subtalar joint (between talus & calcaneous


Which muscles produce the plantarflexion action?

muscles of the posterior compartment of the leg
gastrocnemius, soleus, plantaris & posterior tibialis


Which muscles produce the dorsiflexion movement?

anterior compartment of the leg
tibialis anterior
extensor hallucis longus
extensor digitorum longus


Clinical: which ligament is most likely damaged in ankle sprain?

lateral ligament


Why is the lateral ligament more likely damaged in an ankle sprain?

1. lateral ligament weaker than medial ligament
2. lateral ligament resists inversion (ankle sprain is NORMALLY excessive inversion of ankle joint)


Define an ankle sprain

partial or complete tear in ligaments of the ankle joint


Where does an ankle sprain normally occur?

in a plantarflexed, weight-bearing foot, which is excessively inverted


which lateral ligament is most at risk of IRreversible damage?

anterior talofibular ligament


What is Pott's fracture-dislocation?

a bimalleolar (medial & lateral malleoli) or trimalleolar (medial & lateral malleoli and distal tibia) fracture


How is Pott's fracture-dislocation produced?

there are 3 stages:
1. forced eversion pulls on medial ligaments --> avulsion (pulled out) fracture of medial malleolus
2. talus moves laterally, breaking off lateral malleolus
3. tibia then forced anteriorly, breaking off distal (away) & posterior part against the talus