Structure of ankle joint

Question 1

Type of joint

Answer 1

Synovial hinge joint

Question 2

Articulating bones

Answer 2

Distal tibia and fibula

Talus

Question 3

Freedom of movement

Answer 3

One degree- dorsiflexion and plantarflexion in sagittal plane around a mediolateral axis

Question 4

Closed pack position

Answer 4

Full dorsiflexion
Head of talus wider than gap between distal tibia and fibula so during dorsiflexion fibula laterally rotates and widens gap for talus to fit in during during dorsiflexion

Question 5

Joint capsule

Answer 5

Thin, doesn’t offer much stability

Stability provided by ligaments

Question 6

Medial collateral ligament

Answer 6

Consists of four ligaments than fan out from the malleolus and attach to talus, calcaneus and navicular bones
Limits eversion of foot

Question 7

Lateral collateral ligament

Answer 7

Composed of anterior talo-fibular ligamnet, posterior talo-fibular ligament and calcaneo-fibular ligament
All three proximally attach to lateral malleolus and the talo-fibular ligaments distally attach to the talus and the calcaneo-fibular ligament to the calcaneus
Limits inversion of foot

Question 8

Stability during positioning

Answer 8

Joint is less stable in plantarflexion

Question 9

Which type of sprain is more common?

Answer 9

Inversion sprains more common because the LCL is the only line of defence and the medial ligament is much stronger

Question 10

Arterial supply

Answer 10

From malleolar branches of anterior tibial, posterior tibial and fibular arteries

Question 11

Innervation

Answer 11

Tibial
Superficial fibular
Deep fibular