Flashcards in Tarsal bones (foot) Deck (29):
How are the tarsal bones organised?
Into 3 rows: proximal, intermediate & distal
Describe talus bone of the foot
It is a proximal tarsal bone
Has 3 articulations: superiorly, inferiorly, anteriorly
Main function: transmit force from tibia to calcaneus (heel bone)
Only attaches to ligaments NOT muscles
What are the 3 articulations of the tarsal bone?
Superiorly: ankle joint - between talus & tibia + fibula
Inferiorly: subtalar joint (between talus and calcaneus - under talus)
Anteriorly: talonavicular: between talus and navicular
Proximal tarsal bone of the foot
Has 2 articulations
Thick & sturdy
Transmits force from talus to the ground
Name the 2 articulations of the calcaneus bone
Superiorly: subtalar joint - between talus and calcaneus
Anteriorly: calcaneocuboid joint - between calcaneus and cuboid
What is attached to the calcaneus?
Achilles tendon attached to the calcaneal tuberosity (posterior of calcaneus)
Which bone is in the intermediate tarsal group?
What are the articulations of the navicular bone?
anteriorly: cuneiform bones
What attaches to the navicular? and where?
tibialis posterior tendon
attaches to the plantar (bottom) surface of the navicular to the navicular tuberosity present there
the muscle originates from the interosseous membrane (posterior of tibial)
How many bones are there in the distal tarsal group?
4: cuboid + 3 cuneiforms
What do the distal tarsal bones articulate with?
metatarsals of the foot
Name the cuboid bone's articulations
anteriorly: 2 lateral metatarsals
inferiorly: groove for fibularis longus muscle (inserting into cuboid & base of 1st metatarsal)
fibularis longus originates from later surface of proximal (longus) fibula
Name the articulations of the cuneiforms (lateral, intermediate, medial)
What is the shape of the distal tarsals: cuneiforms? how does this structure help?
3 bones: lateral, intermediate & medial
helps form a transverse arch across the foot
Which bones are most frequently fractured of the tarsal bones and why?
the talus & calcaneus
they transmit forces from the body to the ground
What are the 2 places that a fracture can occur to the talus?
neck & body
clinical: Neck fracture of talus
by excessive dorsiflexion of foot
neck of talus pushed against tibia
blood supply to talus may be disturbed --> avascular necrosis of the bone
Clinical: how does body fracture of talus occur?
normally from jumping from height
How come there is little displacement of the fracture pieces in fracture of talus?
the malleoli of the leg holds the fragments together, so there is little displacement of the fracture pieces
clinical: calcaneus fracture
most common: falling onto heel from height
talus driving into calcaneus
bone can break into several pieces - comminuted fracture
How does the calcaneus x-ray looks like when its fractured?
appear shorter & wider - as comminuted fracture - fractured into several pieces
What are secondary problems of calcaneus fracture? How do you test for this?
sub-talar joint (talus join to calcaneus) usually disrupted
causing joint to become arthritic
pt experience pain when walking esp. on uneven ground as there will be pain upon inversion & eversion
How many metatarsals are there and where are they located?
5 - 1 for each digit
connects phalanges to tarsals
numbered I-V (medial to lateral)
What do each metatarsal consist of?
distal head & proximal base - joined by shaft of bone
Name the articulations of the metatarsal bones
proximally: tarsometatarsal joint (between metatarsal bases & cuneiforms or cuboid)
laterally: intermetatarsal joint (between adjacent metatarsals)
distally: metatarsophalangeal joint (metatarsal head & proximal phalanx)
Clinical: what are the 3 fractures of metatarsal bones that can occur?
1. direct blow e.g. dropping heavy object
2. stress fracture - incomplete fracture from repeated stress e.g. athletes (most common to metatarsals II,III,IV
3. excessive inversion - fibularis brevis can tear off (avulse) base of metatarsal V (F.B. inserts into tuberosity of lateral side of Vth metatarsal)
What are phalanges?
bones of toes
How many phalanges does each toe have?
3 except for the big toe which only has 2
proximal, intermediate & distal
big toe: proximal & distal phalanges