Bones of the Feet Flashcards
What is the purpose of the bones of the foot?
Provide mechanical support for the soft tissues, helping the foot withstand the weight of the body
What can the bones of the foot be divided into?
Tarsals
Metatarsals
Phalanges
What are the tarsals?
A set of seven irregularly shaped bones
Where are the tarsals situated?
Proximally in the foot, in the ankle area
What do the metatarsals do?
Connect the phalanges to the tarsals
How many metatarsals are there?
5- one for each digit
What are the phalanges?
The bones of the toes
What does each toe have?
Three phalanges- a proximal, intermediate and distal, apart from the big two which also has two
How are the tarsal bones organised?
Into three rows, proximal, intermediate, and distal
What are the proximal tarsal bones?
Talus
Calcaneus
What do the proximal tarsal bones form?
The bony framework around the proximal ankle and heel area
What is the most superior of the tarsal bones?
Talus
Where does the talus have articulations?
Superiorly
Inferiorly
Anteriorly
What is formed with the superior articulation of the talus?
Ankle joint
What is the superior articulation of the talus between?
The talus and the bones of the leg (tibula and fibula)
What is formed with the inferior articulation of the talus?
Subtalar joint
What is the inferior articulation of the talus between?
The talus and calcaneus
What is formed with the anterior articulation of the talus?
Talonavicular joint
What is the anterior articulation of the talus between?
Talus and navicular
What is the main function of the talus?
To transmit forces from the tibia to the heel bone (calcaneus)
What is the talus the site of?
Numerus ligament attachments
Where does the calcaneus lie?
Underneath the talus
Where does the calcaneus articulate?
Superiorly
Anteriorly
What is formed with the superior articulation of the calcaneus?
Subtalar joint
What does the calcaneus articulate with superiorly?
The talus
What is formed with the anterior articulation of the calcaneus?
Calcaneocuboid joint
What does the calcaneus articulate with anteriorly?
The cuboid
What does the calcaneus act to do?
Transmit forces from the talus to the ground
What is the posterior aspect of the calcaneus marked by?
The calcaneal tuberosity
What attaches to the calcaneal tuberosity?
The Achilles tendon
What does the intermediate row of tarsal bones contain?
The navicular
What does the navicular articulate with posteriorly?
The talus
What does the navicular articulate with anteriorly?
The cuneiform bones
What does the navicular bone articulate with laterally?
The cuboid bone
What is found on the plantar surface of the navicular?
A tuberosity for the attachment of the tibialis posterior tendon
What are the bones in the distal row of the carpal bones?
Cuboid
Three cuneiforms
What do the carpal bones in the distal row articulate with?
The metatarsals of the foot
What is the most lateral bone in the distal row of the tarsals?
Cuboid
What does the cuboid bone articulate with posteriorly?
The calcaneus
What does the cuboid bone articulate with anteriorly?
Two metatarsals
What is the inferior surface of the cuboid bone marked by?
A groove for the fibularis longus muscle
What are the cuneiforms?
Lateral
Intermediate
Medial
What shape are the cuneiform bones?
Wedge shaped
What do the cuneiforms articulate with posteriorly?
The navicular
What do the cuneiforms articulate with anteriorly?
Metatarsals
Why is the shape of the cunieforms important?
It helps from a transverse arch across the foot
Where do the talus and calcaneus sit?
In the proximal part of the foot and ankle
What are the talus and calcaneus involved in?
Transmitting forces from the body to the ground
What is the result of the talus and calcaneus transmitting forces from the body to the ground?
They are the most frequently fractured of all the tarsal bones
Where can talar farctures occur?
The neck of the talus or the body
What are neck of the talus fracture caused by?
Excessive dorsiflexion of the foot
Why does excessive dorsiflexion of the foot cause neck of the talus fractures?
Because the neck of the talus is pushed against the tibia
What can happen in neck of the talus fracture?
The blood supply to the talus may be disturbed, leading to avascular necrosis of the bone
How do body of the talus fractures usually occur?
From jumping from a heigh
What happens in any fracture of the talus?
The malleoli of the leg bones act to hold the fragments together, so there is little displacement of the fracture pieces
How is the calcaneus most often fractured?
In a ‘crush’ type injury
What is the most common mechanism of injury for a calcaneus fracture?
Falling onto the heel from a height
Why does falling onto the heel from a height cause a calcaneus injury?
The talus is driven into the calcaneus
What can happen when the calcaneus fractures?
The bone can break into several pieces
What is it known as when the bone breaks into several pieces?
A comminuted fracture
How will a comminuted calcaneus appear on a x-ray?
Shorter and wider
Why may a calcaneal fracture cause problems even after treatment?
The sub-talar joint is usually disrupted, causing the joint to become arthritic
When will a patient with an arthritic sub-talar joint experience pain?
Upon inversion and eversion
Where are the metatarsals located?
In the midfoot, between the tarsals and phalanges
What are the metatarsals numbered?
I-V (medial to lateral)
What does each metatarsal consist of?
Distal head Proximal base
Shaft
How many articulations do the metatarsals have?
3 or 4
What is formed in the proximal articulation of metatarsals?
Tarsometatarsal joint
What is involved in the tarsometatarsal joints?
Metatarsal bases and cuneiforms or cuboid bones
What is formed in the lateral articulation of metatarsals?
Intermetatarsal joint(s)
What is involved in the intermetatarsal joint(s)?
Metatarsal and the adjacent metatarsals
What is formed in the distal articulation of the metatarsals?
Metatarsophalangeal joint
What is involved in the metatarsophalangeal joints?
Metatarsal head and the proximal phalanx.
How can metatarsal fractures occur?
Direct blow to foot
Stress fracture
Excessive inversion of foot
What is a stress fracture?
An incomplete fracture caused by repeated stress to the bone
Where does metatarsal stress fractures most commonly occur?
In metatarsals II, III and IV
How can excessive inversion of the foot fracture the metatarsals?
If the foot is violently inverted, the fibularis brevis muscle can avulse the base of metatarsal V
What are the phalanges?
The bones of the toes
What do most toes have?
Three phalanges- proximal, intermediate and distal
What does the great toe have?
Proximal and distal phalanges
