Ankle and Foot

Question 1

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

Answer 1

the ankle

Question 2

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

Answer 2

• 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

Question 3

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

Answer 3

100%

Question 4

When should advanced images be ordered?

Answer 4

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

Question 5

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

Answer 5

85

Question 6

Inversion sprains damage the _____ collateral ligaments

Answer 6

lateral

Question 7

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

Answer 7

Anterior talofibular and calcaneofibular ligaments

Question 8

Eversion sprains damage the _____ collateral ligaments

Answer 8

medial

Question 9

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

Answer 9

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

Question 10

What other injuries are typically associated severe ankle sprains?

Answer 10

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

Question 11

When is joint instability revealed?

Answer 11

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

Question 12

What is a Maisonneurve fracture?

Answer 12

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

Question 13

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

Answer 13

Conservative: Casting
Surgical: Screw fixation followed by immobilization

Question 14

What do ankle fractures frequently occur in combination with?

Answer 14

Ligamentous ruptures, avulsions, and other fractures

Question 15

Generally, what is the MOI for a ankle fracture?

Answer 15

axial or rotational loading

Question 16

What are the 3 anatomically classified ankle fractures?

Answer 16

• Unimalleolar
• Bimalleolar
• Trimalleolar

Question 17

What is a unimalleolar fracture?

Answer 17

A fracture of either the lateral or medial malleolus

Question 18

What is a bimalleolar fracture?

Answer 18

A fracture of both the lateral and medial malleoli

Question 19

What is a trimalleolar fracture?

Answer 19

fracture of both malleoli and the posterior rim of the tibia

Question 20

What are 3 other fractures involving the ankle joint?

Answer 20

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

Question 21

What is the goal when treating ankle fractures?

Answer 21

to stabilize fractures and reestablish architecture of ankle mortise

Question 22

What is the most common complications of an ankle fracture?

Answer 22

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

Question 23

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

Answer 23

Calcaneus

Talus

Question 24

What is the typical MOI for a talus fracture?

Answer 24

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

Question 25

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

Answer 25

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

Question 26

Talar fractures are classified according to what?

Answer 26

Fractures of the talar head, body, or neck

Question 27

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

Answer 27

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

Question 28

What is the treatment for a displaced talar fracture?

Answer 28

Surgery (ORIF) in order to restore subtalar joint congruity

Question 29

What are common complications associated with talar fractures?

Answer 29

• Post-traumatic arthritis of the ankle and subtalar joints

Question 30

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

Answer 30

avascular necrosis

Question 31

What are accessory bones of the foot?

Answer 31

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

Question 32

Accessory bones have an incidence rate as high as __%

Answer 32

30%

Question 33

What are the 3 accessory bones that occur with frequency?

Answer 33

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

Question 34

How do accessory bones complicate the evaluation of foot injuries?

Answer 34

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

Question 35

How can one differentiate between accessory bones and acute fractures?

Answer 35

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.