Ankle & Foot

Question 1

What are the 3 components of the lisfranc joint?

Answer 1

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

Question 2

Where is lisfranc’s ligament

Answer 2

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

Question 3

What is the mechanism of a lisfranc injury?

Answer 3

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

Question 4

What are 5 radiographic findings of a Lisfranc injury?

Answer 4

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

Question 5

What is the normal value for Boehler’s angle?

Answer 5

20-40 degrees

Question 6

What should align on the AP foot view?

Answer 6

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

Question 7

What should align on the oblique foot view?

Answer 7

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

Question 8

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

Answer 8

isolated
homolateral
divergent

Question 9

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

Answer 9

calcaneus

talus

Question 10

Where is Chopart’s joint?

Answer 10

Midtarsal joint (between talus and cuboid/navicular)

Question 11

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

Answer 11

Talus

Question 12

What are minor talar fractures?

Answer 12

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

Question 13

What are major talar fractures?

Answer 13

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

Question 14

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

Answer 14

bilateral 7%
lower extremity 25%
spine fractures 10%

Question 15

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

Answer 15

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

Question 16

What is the Hawkins classification of Talar fractures?

Answer 16

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

Question 17

How do you reduce a talar subluxation/dislocation

Answer 17

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

Question 18

What bones are at risk of AVN?

Answer 18

Scaphoid
Lunate
Navicular
Talus
Femoral head
Odontoid

Question 19

What is the most common site of talar fractures?

Answer 19

Talar neck

Question 20

What is the most common mechanism of talar dislocations?

Answer 20

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

Question 21

What is the difference between subtalar and total talar dislocation?

Answer 21

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

Question 22

What is a mimic for ankle sprain with prolonged pain?

Answer 22

Osteochondral defect on talar dome

Question 23

What injury is missed on the Ottawa ankle rule?

Answer 23

Osteochrondral talar dome fracture

*can be picked up on bone scan

Question 24

What other orthopedic injuries should you consider in calcaneus fractures?

Answer 24

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

Question 25

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

Answer 25

Fall from height, axial load to feet

Question 26

What are calcaneus fractures at risk for?

Answer 26

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

Question 27

What is the general management of calcaneus fractures?

Answer 27

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

Question 28

What is the mechanism of navicular avulsion fracture? Management?

Answer 28

Extreme plantarflexion Non weight bearing boot Ortho F/U

Question 29

What is a nutcracker injury?

Answer 29

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

Question 30

What are cuboid fractures associated with?

Answer 30

Lisfranc | Other foot fractures

Question 31

What are Xray findings of calcaneus stress fractures?

Answer 31

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

Question 32

What is the ddx of heel pain?

Answer 32

``` 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 ```

Question 33

What is os trigonum syndrome?

Answer 33

Seen in ballet dancers | Compression of os trigonum in plantar fracture