tibia, fibula, and ankle joints Flashcards
what is the significance of the tibial tuberosity
where the patella tendon attaches to the tibia
why is the anterior border of the tibia susceptible to fracture
so close to the skin
is the soleus line anterior or posterior
posterior
what is the soleal line
where the soleus muscle attaches
action of soleal muscle on the tibia
helps maintain posture due to the centre of gravity lying anterior to the tibia
why can fractures of the distal 1/3 of the tibia take longer to heal compared to the proximal 2/3
because the blood supply here isnt as good as the bone is thinner hear
what makes up the lateral and medial malleolus at the ankle and which is bigger
medial malleolus - distal tibia lateral malleolus - distal fibula (extends further distally)
major roles of the tibia and fibula
tibia - weight bearing fibula - non weight bearing, for muscle attachment
is the tibial tuberosity anterior or posterior
anterior
why is it easy to get ring hypophyses fractures of the tibia and fibula
because they are connected via the interosseous membrane
what is the function of the interosseous membrane between the tibia and fibula
passage of vessels
what kind of joints are the superior and inferior tibiofibular joints
superior = plane synovial joint inferior = fibrous joint (syndesmosis)
what structures help stabilise the superior tibiofibular joint
- anterior and posterior tibiofibular ligaments - fibular collateral ligament (attaches to head of the fibula) - head of one of the hamstring muscles attaches to fibula
what is the importance of the stability of the inferior tibiofibular joinw
it allows us to be bipedal - it prevents tibia and fibula from separating during weight bearing
what structures help stabilise the inferior tibiofibular joint
anterior and posterior interosseous tibiofibular ligaments
which joint is least likely to dislocate? the superior or inferior tibiofibular joint
superior (inferior very unlikely)
what is the malleolar mortise
the distal end of the fibula forms a socket for the talus bone of the foot
what are the names of the tarsal bones and how are they arranged
3 rows: 1st row: calcaneus and talus 2nd row: cuboid and navicular 3rd row: medial, intermediate and lateral cuneiforms
which tarsal bone is the “heel”
calcaneous
which tarsal bone articulates at the ankle joint
the talus bone (only bone to articulate here)
where does the archilles tendon attach
to the posterior border of the calcaneus tarsal bone
which muscle is the archilles tendon part of
soleus
which bones articulate anteriorly with the talus and the calcaneous bones
talus = navicular calcaneous = cuboid
what is a March fracture
fracture of the 2nd metatarsal
why is the 2nd metatarsal most likely to fracture
because it is the longest and thinnest metatarsal and its articulation with the tarsal is very wedged in between the first and third
functions of sesamoid bones in the foot
- cushioning effect - can create a space for nerves and vessels to run through
what are accessory bones in the foot
secondary centres of ossification that dont fuse with the parent bone
what are the 3 joints that the talus bone is a part of
ankle joint above (talocrural joint) subtalar joint below (talcalcaneal joint) midtarsal joint in front (talocalcaeneonavicular and calcaneocuboid)
what “deepens” the ankle joint posteriorly
the inferior transverse ligament
movement at the ankle joint
flexion (plantar flexion) and extension (dorsiflexion) only - hinge joint (have associated slight inversion and eversion)
association of inversion and eversion with dorsiflexion and plantar flexion of the ankle joint
plantar flexion associated with some inversion dorsi flexion associated with some eversion
what causes the slight inversion and eversion of the foot with dorsi and plantar flexion
due to the lateral malleolus being longer distally than the medial malleolus
is dorsi or plantar flexion more stable and why
plantar flexion is more stable because anterior articulation of the talus bone is wider anteriorly compared to posteriorly
what is the main medial ligament of the ankle joint
deltoid ligament - very strong
what are the main lateral ligaments of the ankle joint
3 lateral collateral ligaments
is eversion or inversion sprains of the ankle more common
inversion - because the deltid ligament is much more stable than the lateral collateral ligaments - therefore lateral collateral ligaments injured more often
inversion of the ankle joint is associated with what fracture
fracture of the malleolus of the fibula (because the body of the talus is pushing on the lateral malleolus outwards)
what is a Pots fracture
fracture of the fibula due to forced eversion of the ankle joint
which joint is associated with inversion and eversion of the ankle
the subtalar joint (between talus and calcaneous)
function of the spring ligament in the foot
maintains the position of the head of the talus
what is the proper name for the spring ligament of the foot
the plantar calcaneo-navicular ligament
what is the sinus tarsi
slight gap between the subtalar and TCN joints - where the interosseous talocalcaneal ligament runs and also where the vascular sling runs
function of the interosseous talocalcaneal ligament
binds calcaneus and talus firmly together
what is pronation and supination of the foot joints
pronation = eversion and lateral rotation supination = inversion and medial rotation
action of the calcaneocuboid joint
helps in pronation and supination
what are the Lisfranc joints
the tarsometatarsal joints
what are the 3 arches of the arches of the foot
2 longitudinal arches (medial and lateral) 1 transverse arch
is the medial or lateral longitudinal arch of the foot higher
medial as it is supported by ligaments and muscles
what kind of support is needed for the arches of the foot in dynamic and static activity
dynamic activity = muscular support static activity = ligamentous upport
what is the Windlass effect of the plantar aponeurosis
dorsiflexion of the toes during propulsive phase of gait causes tightening of the plantar aponeurosis –> causes elevation of the longitudinal arch - leading to a forced supination of the foot in preparation for the push off during gait
