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Flashcards in Ankle & Foot Deck (33):
1

What are the 3 components of the lisfranc joint?

Tarsometatarsal joint
- tarsometatarsal articulation
- intermetatarsal articulation
- intertarsal articular
1st-3rd metatarsals + cuneiforms and 4-5th metatarsals with cuboid

2

Where is lisfranc's ligament

connects the lateral aspect of the medial cuneiform to the medial aspect of the proximal 2nd metatarsal

3

What is the mechanism of a lisfranc injury?

extreme dorsiflexion
dorsiflexion on a plantarflexed foot
rotation about a fixed forefoot

orthobullets: mechanism is usually caused by indirect rotational forces and axial load through hyperplantar flexed forefoot

4

What are 5 radiographic findings of a Lisfranc injury?

Widening between 1st and 2nd metatarsal
Failure of metatarsal-tarsal alignment (especially second on AP, 3rd on oblique)
Dorsal step off of the MT and tarsals on the lateral
Associated fractures – cuboid, cuneiforms, 1st metatarsal
Fleck sign – avulsion at the base of 2nd metatarsal

5

What is the normal value for Boehler's angle?

20-40 degrees

6

What should align on the AP foot view?

medial aspect of 2nd metatarsal and medial aspect of intermediate cuneiform

7

What should align on the oblique foot view?

medial aspect of 3rd metatarsal and medial aspect of lateral cuneiform

8

What are 3 categories of Lisfranc injuries (description of directions)

isolated
homolateral
divergent

9

What are the 2 most common bones fractured in the foot?

calcaneus
talus

10

Where is Chopart's joint?

Midtarsal joint (between talus and cuboid/navicular)

11

What is the only bone in the lower extremity without muscle insertion?

Talus

12

What are minor talar fractures?

Chip/avulsion #'s of:
Superior head and neck
Lateral/medial/posterior portions of body
Osteochondral dome fractures

13

What are major talar fractures?

Talar head 10%
Talar neck 50%
Talar body 25%

14

What is the incidence of associated injuries with calcaneus fractures (3)?

bilateral 7%
lower extremity 25%
spine fractures 10%

15

What is Gissane's angle composed of and what is the normal range?

formed by 2 strong cortical struts - lateral margin of the posterior facet and the anterior beak of the calcaneus
105-135 degrees

16

What is the Hawkins classification of Talar fractures?

I: Fracture with displacement but no sublux/dislocation
II: Fracture with subluxation
III: Fracture with dislocation

17

How do you reduce a talar subluxation/dislocation

Foot in plantarflexion
Longitudinal traction with lateral or medial pressure to achieve reduction
grap by calcaneus

18

What bones are at risk of AVN?

Scaphoid
Lunate
Navicular
Talus
Femoral head
Odontoid

19

What is the most common site of talar fractures?

Talar neck

20

What is the most common mechanism of talar dislocations?

Plantarflexion
In plantarflexion - posterior aspect of talus is smaller, less area and easier to dislocate anteriorly
Anterior aspect is fatter, wedged

21

What is the difference between subtalar and total talar dislocation?

Subtalar: talonavicular and talocalcaneus disruption but tibiotalar still intact
Total talar dislocation: tibiotalar disrupted as well

22

What is a mimic for ankle sprain with prolonged pain?

Osteochondral defect on talar dome

23

What injury is missed on the Ottawa ankle rule?

Osteochrondral talar dome fracture
*can be picked up on bone scan

24

What other orthopedic injuries should you consider in calcaneus fractures?

Bilateral
Spine (lumbar)
Lower extremity (tib/fib -plateau, femur, pelvis)
Other foot fracture

25

What is the most common mechanism of injury for calcaneus fractures?

Fall from height, axial load to feet

26

What are calcaneus fractures at risk for?

Compartment syndrome
Nonunion, malunion
Post traumatic arthritis
CRPS
Soft tissue loss

27

What is the general management of calcaneus fractures?

+/- CT
Orthopedics consultation
Immobilization in dorsiflexion splint vs. boot
Assess for other injuries

28

What is the mechanism of navicular avulsion fracture? Management?

Extreme plantarflexion
Non weight bearing boot
Ortho F/U

29

What is a nutcracker injury?

Forceful eversion of foot
Cuboid is crushed between calcaneus and forefoot
*cuboids are RARE for isolated injuries

30

What are cuboid fractures associated with?

Lisfranc
Other foot fractures

31

What are Xray findings of calcaneus stress fractures?

Increased linear opacification (white) perpendicular to the normal lines of the calcaneus

32

What is the ddx of heel pain?

Plantar fasciitis (worst in morning, with rest)
Plantar fascial rupture
Calcaneus fracture
Calcaneus stress fracture
Os trigonum syndrome
Plantar spurs
Subcalcaneal bursitis
Arthritis
Nerve compression

33

What is os trigonum syndrome?

Seen in ballet dancers
Compression of os trigonum in plantar fracture