Ankle & Foot Flashcards
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
Where is lisfranc’s ligament
connects the lateral aspect of the medial cuneiform to the medial aspect of the proximal 2nd metatarsal
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
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
What is the normal value for Boehler’s angle?
20-40 degrees
What should align on the AP foot view?
medial aspect of 2nd metatarsal and medial aspect of intermediate cuneiform
What should align on the oblique foot view?
medial aspect of 3rd metatarsal and medial aspect of lateral cuneiform
What are 3 categories of Lisfranc injuries (description of directions)
isolated
homolateral
divergent
What are the 2 most common bones fractured in the foot?
calcaneus
talus
Where is Chopart’s joint?
Midtarsal joint (between talus and cuboid/navicular)
What is the only bone in the lower extremity without muscle insertion?
Talus
What are minor talar fractures?
Chip/avulsion #’s of:
Superior head and neck
Lateral/medial/posterior portions of body
Osteochondral dome fractures
What are major talar fractures?
Talar head 10%
Talar neck 50%
Talar body 25%
What is the incidence of associated injuries with calcaneus fractures (3)?
bilateral 7%
lower extremity 25%
spine fractures 10%
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