MSK - The Ankle Joint Flashcards Preview

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Flashcards in MSK - The Ankle Joint Deck (26)
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1
Q

What type of joint is the ankle joint?

A

Synovial hinge type joint

2
Q

What bones form the ankle joint?

A

Tibia

Fibula

Talus

3
Q

What actions does the ankle joint permit?

A

Dorsiflexion and planterflexion

4
Q

What are the tibia and fibula bound together by?

What type of socket does this produce?

What is this socket called?

A

Strong tibiofibular ligaments

Bracket type socket

Mortise

5
Q

What shape is the articulating part of the talus?

Where is it largest and where is it thinnest?

A

Wedge Shapes

Thicket posteriorly and thinnest anteriorly

6
Q

During dorsiflexion, what part of the talus is held by the mortise?

Is the joint more stable in dorsiflexion or plantarflexion?

A

Anterior part

Dorsiflexion

7
Q

During planterflexion, what part of the talus is held in the mortise?

A

Posterior

8
Q

What colour is the talus?

A

Yellow

9
Q

How many sets of ligaments are there at the ankle joint?

Where do they originate?

A

Two

Originate from each malleolus

10
Q

Where does the medial ligament originate from?

How many ligaments make up the medial ligament?

What is its main function?

A

Medial Malleolus

4

Resist over-eversion of the foot

11
Q

Where does the lateral ligament originate from?

What is its main function?

How many ligaments make up the medial ligament?

A

Lateral malleolus

Resists over-inversion of the foot

3

12
Q

What are the three ligaments that make up the lateral ligament?

Where do they span between?

A

Anterior talofibular - Spans between the lateral malleolus and lateral aspect of the talus

Posterior talofibular - Spans between the lateral malleolus and the posterior aspect of the talus

Calcaneofibular - Spans between the lateral malleolus and the calcaneum

13
Q

Label the ligaments that make up the lateral ligament of the ankle joint

A
14
Q

The ankle joint and associated ligaments can be visualised as a ring in the coronal plane

What forms the upper part of the ring?

A

Upper Part - Formed by the articular surfaces of the tibia and fibula

15
Q

The ankle joint and associated ligaments can be visualised as a ring in the coronal plane

What forms the lower part of the ring?

A

Lower part - Formed by the subtalar joint (between the talus and the calcaneus)

16
Q

The ankle joint and associated ligaments can be visualised as a ring in the coronal plane

What forms the sides of the ring?

A

Sides - Formed by the medial and lateral ligaments

17
Q

What must you bear in mind when dealing with an injury to the ankle joint?

Why?

A

A fracture of the ankle joint may occur in association with ligament damage – which would not show up on x-ray

A ring, when broken, usually breaks in two places

18
Q

What muscles are involved in Plantarflexion of the foot?

A

Produced by the muscles in the posterior compartment of the leg; gastrocnemius, soleus, plantaris and posterior tibialis

19
Q

What muscles are involved in dorsiflexion of the foot?

A

Produced by the muscles in the anterior compartment of the leg; tibialis anterior, extensor hallucis longus and extensor digitorum longus

20
Q

What does an ankle sprain refer to?

A

Partial or complete tears in the ligaments of the ankle joint

21
Q

When does ankle sprain usually occur?

A

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

22
Q

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

A

The lateral ligament is weaker than the medial ligament

The lateral ligament resists inversion

23
Q

What ligament making up the lateral ligament is most at risk of irreversible damage?

A

Anterior talofibular

24
Q

What has happened in this picture?

A

Pott’s fracture (bimalleolar) of the ankle joint

25
Q

Pott’s fracture is used to describe what?

A

Any bimalleolar fracture (i.e. a fracture of both the medial and lateral malleoli)

26
Q

How does a bimalleolar fracture occur?

A

This type of injury occurs via forced eversion, in a series of stages:

1 - Forced eversion pulls on the medial ligaments, producing an avulsion fracture of the medial malleolus

2 - The talus moves laterally, breaking off the lateral malleolus

3 - The tibia is then forced anteriorly, shearing off its distal, proximal portion against the talus