Flashcards in The ankle joint Deck (28):
What type of joint is the ankle joint? (name both)
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?
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?
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?
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
extensor hallucis longus
extensor digitorum longus
Clinical: which ligament is most likely damaged in ankle sprain?
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