Bones of the foot

Question 1

Describe the structures of the bones of the foot?

Answer 1

Provide mechanical support for the soft tissues, help the foot withstand the weight of the body whilst standing and in motion. Can be divided into three groups:
Tarsals- seven ireegulary shaped bones
Metatarsals- connect the phalanges to the tarsals
Phalanges- bones of the toes, each toe has three phalanges except the big toe which has two

Question 2

Name the seven tarsals

Answer 2

Calcaneus- heel
Talus
Navicular- boat
Cuboid
3x cuniforms

Question 3

Describe the talus

Answer 3

Most superior of tarsal bones, transmits the weight of the entire body into the foot. It has three articualtions:
Superiorly- ankle joitn between talus, tibia and fibula
Inferiorly- subtalar joint between the talus and calcaneus
Anteriorly- talonavicular joint- between talus and navicular
Talus is at high risk of avascular necrosis as many ligaments attach to it but not many originate or insert into it

Question 4

Describe the calcaneus

Answer 4

The largest tarsal bone it lies underneath the talus where it constitutes the heel. It has two artiulations
Superiorly: Subtalar- between the calcaneus and talus
Anteriorly: Calaneocuboid joint- between calcaneus and cuboid
Protrudes posteriorly and takes the weight of the body as the heel hits the ground when walking Posteriorly marked by the calcaneal tuberosity which the achilles tendon attaches

Question 5

Describe the structure of the cuniform

Answer 5

Contain three wedge shaped bones:Lateral, medial and intermediate. Articulate with the navicular posteriorly and the metatarsals anteriorly.Shape of the bones help form a transverse arch across the foot.
Medial cuniform- attachment of tibialis anterior and part of tibialis posterior and fibularis longus
Lateral cunifotm- flexor hallicus brevis

Question 6

What are the most commonly fractured bones of the foot?

Describe what occurs in a talur fracture?

Answer 6

Talus and calcaneus

Neck fracture- typically high energy fractures- typically high energy fractures caused by excessive dorsiflexion of the foot. Neck of talus gets pushed against the tibia. In this type of fracture the blood supply to the talus may be disturbed leading to avascular necrosis of the bone.
Body fracture- usually occur from jumping from a height
Typically malleoli of the leg bones hold the foot together so there is little displacement.

Question 7

Describe what happens during a calcaneus fracture

Answer 7

Typically occurs from axial loading typically from falling from a height. These patients should be assessed for associated injuries such as fractures od the lumbar spine or lower line. Even after treatment it can cause further problems. Typically experience arthritis. The patient will experience pain upon inversion and eversion making walking on uneven ground painful

Question 8

Describe the metatarals

What are the four articualtions of the metatarsals

Answer 8

Located in the forefoot between tarsals and phalanges. They are numbered I-V (medial to lateral). Each metatarsal has similar structures they convex dorsally and consist of a head, neck, shaft and base
Proximally- tarsometatarsal joints- between the metatarsal bases and tarsal bones
Laterally- intermetatarsal joints- between the metatarsal and the adjacent metatarsals
Distally- Metatarsophalangeal joints- between the metatarsal head and the proximal phalanx

Question 9

What causes a metatarsal fracture

Answer 9

Direct blow to the foot,
Stress fracture- caused by repeated stress on the bone and occurs most frequently at the necks of the second and third metatarsals and proximal fifth metatarsal
Excessive inversion can tear base of fifth metatarsal

Question 10

What are the phalanges?

Answer 10

Bones of the toes, each toe has three (proximal, distal and middle phaalnges) Big toe only has proximal and distal. Just like metatarslas they have a base, shaft and head