x-ray anatomy ankle

Question 1

why is it important to angle the foot so you get a proper mortis view

Answer 1

so if there is any widening of joint space can be identified

Question 2

assess medial and lateral side of AP ankle for any soft tissue swelling

Question 3

on the lateral ankle view, look out for anterior joint effusion. this can be seen as an area of increased density that pushed out the adjacent fat plane

Question 4

where are the 3 accessory ossicles found in the ankle

Answer 4

• tip of lateral and medial malleolus
• posterior to the talus

Question 5

as the ankle is a ring structure, if theres one fracture, another should be sought. However this is not always the case, what is the other possibility and what does this cause?

Answer 5

• ruptured ligament which is shown through widened joint space

Question 6

what 3 ligaments are responsible for joint space in the ankle

Answer 6

• medial / lateral collateral ligaments
• interosseous ligament

Question 7

how can the rupture of the medial, lateral and interosseous ligament affect joint space

Answer 7

• medial/lateral affects the joint space between medial malleolus / tibial head and the talus
• interosseous affects the joint space between the lateral malleolus and talus/ tibia

Question 8

the joint space between the distal tibia and fib must be how wide, otherwise indicating injury

Answer 8

6mm

Question 9

what is a Maisonneuve fracture/injury

Answer 9

• rotative injury causing transverse fracture of medial malleolus and fracture of proximal 3rd shaft of fibula

Question 10

toddler fracture = spiral fracture of the tibia

Question 11

the talar dome should be scrutinised for subtle indentation of joint surface or small detached fragments.

This is evidence of OSTEOCHONDRAL fracture.

Question 12

what is osteocondritis dissecans and what part of the ankle is likely to get this and what are radiographic signs of it

Answer 12

a joint condition in which bone underneath the cartilage of a joint dies due to lack of blood flow.

• the talus is prone and you will see sclerotic margins

Question 13

true subtler dislocation = dislocation of talonavicular and talocalcaneal joints displaces with foot

Question 14

how can you identify compressive fractures of an ankle

Answer 14

using the lateral projection, you measure the bohlers angle

(parallel line from highest posterior point + parallel line from highest anterior point of calcaneum)
- right angle should be around 30 degrees +