ankle and foot anatomy Flashcards
Name the lateral ligaments of the ankle?
Which is the strongest and weakest?
- Anterior talofibular ligament
- Calcaneofibular ligament
- Posterior talofibular ligament
- Syndesmosis includes- AITFL, PITFL, TTFL, IOL, ITL
- Ant talofibular -weakest
- Post talofibular lig - strongest
Name the medial ankle ligaments?
- Deltoid
- Calcaneonavicular ligament - Spring ligament
What is the main stabiliser in stance phase of gait ?
Deltoid ligament
What is the deltoid ligament made up of?
- Deep and superficial ligaments
-
Superficial
- crosses both ankle and subtalar joints
- tibiocalcaneal ( sustenaculum portion ) is strongest portion in superificial layer and resists calcaneal eversion
-
Deep
- only crosses ankle joint
- primary stabiliser of medial ankle
- prevent lateral displacement & external rotation of talus
- originates inferior and posterior aspects of medial malleolus and inserts medial adn posterolateral aspects of talus and inserts medial posteromedial aspects of talus
How do you test the deltoid ligament?
- eversion test
- with ankle in neutral , evaluates superificial layer
- external rotation stres test evaluates syndesmosis and deep layer
What investigations is helpful to dx deltoid lig injury?
Xray
- Mortice view with medial clear space widening
- Gravity stress view
MRI
- rutured Deltoid ligament
What is the function of the spring ligament?
- Static stabiliser of the medial longitudinal arch and head of talus
Describe the anatomy of the spring ligament- Calcaneonavicular?
- Attaches from sustentaculum tali to inferior aspect of navicular
What is seen clliniclly in a pt with spring lig injury?
- Flattening of medial longitudinal arch
- s_uspect injury in associated posterior tibial tendon patholog_y
What investigations are useful in dx of spring ligament injury?
MRI
- can dx tear
- green on pic normal , red is torn
- spring ligament ca be torn is association of tibialis posterior insufficiency or an acute tear with intact TP
What is the function of the syndesmosis?
what is the syndemosis made up of?
- intregrity of ankle mortice
anatomy
- Anterior- inferior tibiofibular ligament (AITFL)
- posterior- inferior tibiofibular ligmament (PITFL)
- Transverse tibiofibular ligament (TTFL)
- Interosseous ligament (IOL)
What is the imaging useful for DX a syndemotic injury?
Xarys
- Ap and mortise ankle radiographs
- evaluate the clear space adn tibiofibular overlap
- tibiofibular clear space should be <5mm
- Tibiofibular overlap for AP view >10mm
- WB mortise view most accurate to dx
CT scan
- Most accurate assessment
What bones comprise the hindfoot ?
Talus Calcaneus Cuboid
What joints make up the hindfoot ?
Subtalar Calcaneocuboid Talobavicular
What is he function of the hindfoot ? Which one is greater ?
- Inversion
- Eversion
- Inversion usually greater.
- Limited eversion contributes further to mild cavovarua foot deformity
Where for the midfoot begin articulation?
- Between navicular and cuneiforms
- along with the cuboid and 4th and 5th metatarsals.
- Included the tarsometarsal joints
What is the function of the midfoot ?
- In adduction and abduction
What is the name for the talonavicular and calcaneocuboid joints?
- Chopard or midtarsal or transverse tarsal
What is important about chopart joint? Explain how?
- Provides stability of hindfoot and midfoot to produce a rigid lever at heel rise
- On heel strike- transverse tarsal joints are parallel and supple- adapt uneven ground
- During toe off- joints become divergent and lock- stiff to foot for forward propulsion
What is the collective name for the Tmt joint?
Lisfranc
How many columns has the forefoot ? Name them?
3
- Medial
- Middle
- lateral
What is in the medial column?
- 1st metatarsal
- medial cuneiform
- navicular
What is in the middle column?
- 2/3 rd metatarsals
- Middle cuneiform
- Lateral cuneiform
What is in the lateral column ?
- 4:5 th metatarsal
- Cuboid
Which Column is the most flexible?
- The lateral column
- Aids flexibility on uneven grounds
Name the 2 arches in the foot?
- Longitudinal
- Transverse
Name the primary stabiliser of the longitudinal arch?
The interosseous ligament
Name the sexondary stabiliser of the longitudinal arch?
- The plantar fascia
Where is the location of the lis franc ligament ?
- Between the medial cuneiform and base of 2nd metatarsal
What does the forefoot consist of?
Includes all structures distal to Tmt joints
Which MT s longer ? Why is this important
- 2nd
- Risk of stress fracture greatest
Which MT is the shortest ? What is the clinical significance ?
- The 1st- shorter and wider
- Bears 50% weight during gait
Name what balances the lesser toes?
- Extrinsic ligaments - extensor digitorum longus , flexor digitorum longus
- Instrinics-interossei, lumbricals- allow Flexion at mcpj and extension at pipj
- Passive restraints- joint capsule, plantar plate, extensor hood, collateral ligaments
Describe the position of the intrinsics tendons
- The tendons pass plantar- Flexion force to the mtp joint axis proximally and pass dorsal to the axis distally ( provide extension to pipj)
What happens when this axis migrates plantar ?
- Post weils osteotomy ( oblique shortening) of the mt heads leads to cock up toe- tendons are now relatively dorsal to the mtp axis of rotation
What happens when unstrung a are lost?
In hereditary and sensory neuropathy or diabetic neuropathy -> claw toes
Can you decribe the function of the ankle ligaments?
- The calcaneofibular ligament becomes most taut with the ankle dorsiflexed and inverted.
- The anterior talofibular ligament is most tensioned with the ankle plantarflexed and inverted.
- The anteriorandposterior tibiofibular ligaments contribute stability to the tibiofibular articulation and syndesmosis.
- The deltoid ligament is the primary stabilizer medially and is stressed with ankle eversion testing.
