Ankle and Foot Flashcards Preview

633: Human Imaging II > Ankle and Foot > Flashcards

Flashcards in Ankle and Foot Deck (35):
1

What is the most frequently injured major joint in the body?

the ankle

2

When should ankle radiographs be ordered according to the Ottawa ankle and foot rules?

- If the patient unable to bear weight
- If there is point tenderness in either malleolar zone, mid-foot zone, base of fifth metatarsal, or at the navicular

3

The Ottawa ankle and foot rules are __% sensitive for detecting significant fractures

100%

4

When should advanced images be ordered?

When radiographic findings are...
Insufficient to guide treatment
- After radiographic findings are negative when further injury is suspected

5

Inversion ankle sprains account for __% of all traumatic conditions at ankle

85

6

Inversion sprains damage the _____ collateral ligaments

lateral

7

What ligaments are the most frequently injured components of the LCL system

Anterior talofibular and calcaneofibular ligaments

8

Eversion sprains damage the _____ collateral ligaments

medial

9

Are inversion or eversion sprains generally associated with bony damage? Explain why

Eversion, because the MCL has so much tensile strength that avulsion fractures and other fractures often occur before the MCL itself fails structurally and sustains damage

10

What other injuries are typically associated severe ankle sprains?

- avulsion fractures
- tearing of the distal tibiofibular syndesmotic complex
- ankle instability

11

When is joint instability revealed?

On routine radiographs or stress views by observing an abnormal position of the talus or increased width of ankle mortise

12

What is a Maisonneurve fracture?

An ankle sprain that disrupts the interosseous membrane a produces a spiral fracture at the proximal fibula

13

What are the 2 treatment options to restore the stability of the ankle mortise?

Conservative: Casting
Surgical: Screw fixation followed by immobilization

14

What do ankle fractures frequently occur in combination with?

Ligamentous ruptures, avulsions, and other fractures

15

Generally, what is the MOI for a ankle fracture?

axial or rotational loading

16

What are the 3 anatomically classified ankle fractures?

- Unimalleolar
- Bimalleolar
- Trimalleolar

17

What is a unimalleolar fracture?

A fracture of either the lateral or medial malleolus

18

What is a bimalleolar fracture?

A fracture of both the lateral and medial malleoli

19

What is a trimalleolar fracture?

fracture of both malleoli and the posterior rim of the tibia

20

What are 3 other fractures involving the ankle joint?

- Shaft fractures of the fibula and tibia
- Comminuted fractures of the distal tibia
- Intra-articular fractures of the tibial plafond or talar dome

21

What is the goal when treating ankle fractures?

to stabilize fractures and reestablish architecture of ankle mortise

22

What is the most common complications of an ankle fracture?

non-union and degenerative joint changes associated with post-traumatic arthritis

23

What type of foot fracture is the most common? What is second?

Calcaneus

Talus

24

What is the typical MOI for a talus fracture?

Tends to occur when a large force is applied through a dorsiflexed foot such as when a driver slams on their brakes in an auto collision

25

Are talar fractures considered intra-articular or extra-articular type fractures? Why?

Intra-articular, because ⅗ of the talus is covered with articular cartilage

26

Talar fractures are classified according to what?

Fractures of the talar head, body, or neck

27

What is the treatment for a non-displaced talar fracture?

immobilization in short-leg cast for 8-12 weeks and avoidance of weight-bearing for initial 6 weeks until radiographic evidence of healing

28

What is the treatment for a displaced talar fracture?

Surgery (ORIF) in order to restore subtalar joint congruity

29

What are common complications associated with talar fractures?

- Post-traumatic arthritis of the ankle and subtalar joints

30

Because the talus lacks blood supply what is it at risk of developing?

avascular necrosis

31

What are accessory bones of the foot?

Anomalous bones that usually form because of failure of one or more ossification centers to unite with the main mass of bone

32

Accessory bones have an incidence rate as high as __%

30%

33

What are the 3 accessory bones that occur with frequency?

- intermetatarsal ossicle (os intermetatarsale)
- external tibial ossicle (os tibiale externum)
- trigone ossicle (os trigonum)

34

How do accessory bones complicate the evaluation of foot injuries?

When present in the area of a suspected fracture they can mistaken for one

35

How can one differentiate between accessory bones and acute fractures?

Accessory bone have an intact, smooth cortical shell with an underlying line of increased density.
Whereas acute fractures have an irregular cortical surface and there is no appearance of increased density beneath the surface.