feet, ankle, tib and fib

Question 1

find a diagram and label the talus bones

Question 2

what 5 bond landmarks can be found on the foot/ankle

Answer 2

• medial/lateral malleoli
• base of 5th metatarsal
• metatarsophalangeol joint/ metatarsal heads
• tubercle of navicular
• calcaneal tuberosity

Question 3

what should you see on a DP foot xray

Answer 3

• entire foot and soft tissue
• metatarsals are equally spaces
• superimposition of tarsals and metatarsal bones
• body trabecular detail and soft tissue outline

Question 4

which direction is the foot turned for an oblique foot xray

Answer 4

Eversion, towards medial side , medial rotation

Question 5

what should be seen on an oblique dp foot xray

Answer 5

• 3-5 metatarsals free of superimposition
• bases of first and second metatarsals superimposed on medial and intermediate cuneiforms
• navicular, lateral cuneiform and cuboid with less superimposition than in DP projection

Question 6

what should be seen on a lateral foot xray

Answer 6

• entire foot
• ankle joint
• superimposed plantar surfaces of metatarsal heads
• bony trabecular detail
• sot tissue

Question 7

difference between dorsi and plantar flexion

Answer 7

• dorsiflexion = 90 degree with feet
• plantar flexion = point foot

Question 8

why must the foot not droop when taking an ankle xray

Answer 8

• it will cause the calcareous to be superimposed by the fibula

Question 9

what is an AP ankle view also known as

Answer 9

mortice view

Question 10

what should be seen on a lateral ankle xray

Answer 10

• distal end of fibula projected over posterior half of distal tibia
• talar dome superimposed with clear joint space
• base of 5th metatarsal included
• bony trabecular detail
• soft tissue

Question 11

what is the typical secondary ossicle found on the tip of the lateral malleolus, not to be confused with an avulsion fracture

Answer 11

• os subfibulare

Question 12

where would you centre for a lateral calcaneus view

Answer 12

• 2.5cm distal to medial malleolus

Question 13

what should you see on a lateral calcaneus view

Answer 13

• no rotation
• talar dome superimposed and tuberosity in profile
• sinus tarsi open
• calcaneocuboid and talonavicular joints open

Question 14

what is the sinus tarsi

Answer 14

a small hollowed out space between the calcaneus (heel bone) and the talus (ankle bone), which together form the subtalar joint.

Question 15

what does the sinus tarsi contain and what is its main function

Answer 15

• contains ligament, nerves, blood vessels
• controls stability of ankle and important for balance and proprioception (sense of self-movement and body position)

Question 16

what is the sustentaculum tali and what is its main function

Answer 16

• horizontal bony shelf that articulates with talus
• essential for standing upright and prevents ankle rolling inwards upon weight bearing

Question 17

what is bohlers angle

Answer 17

• a line drawn from the superior point of the posterior calcanea tuberosity to the highest midpoint of the posterior articular facet
  AND
• a line from the highest midpoint of the posterior articular facet to the anterior process

Question 18

what is the average bohlers angle

Answer 18

20-40 degrees

Question 19

what should you see on an axial calcaneus

Answer 19

• no rotation
• 1st and 5th metatarsals not projected over calcaneum
• subtler joint clear and open

Question 20

why must the knee and ankle joints be included on a tib and fib xray

Answer 20

as the proximal end of fib may also be fractured if there is a fracture of distal fib, tibia or widening of mortise joint

Question 21

why is it assumed that a fracture of distal or proximal end of tib or fib spans across the whole shaft

Answer 21

• due to the bony ring rule
• (if you see a fracture or dislocation in a ring bone or ring bone equivalent, look for another fracture or dislocation.)

hence the entire length of both bones must be demonstrated in scan

Question 22

what is another name of the toe

Answer 22

hallux

Question 23

where is the centering point of big toe lateral

Answer 23

first metotarsal-phalangeal joint

Question 24

what should be seen on a lateral big toe xray

Answer 24

• distal and proximal phalange
• distal 2/3rd of metatarsal
• clear joint spaces

Question 25

why is a lateral toe projection important in terms of diagnosis

Answer 25

• good for hyeprflexion (stubbing) injuries
• undisplayed avulsion fracture of distal phalanx of big toe can be missed on DP or DP oblique big toe scan

Question 26

for DP toes, the tube may be raised by what degree of angle

Answer 26

15 degrees

Question 27

where is the centering point for toe xrays

Answer 27

at the metatarsal-phalangeal joint of affected toe

Question 28

what must be included on toe xray

Answer 28

affected toe up to the distal phlanx, down to 1/3rd of metatarsal and adjacent toe

Question 29

what angle must the foot be leaned medially for DP oblique

Answer 29

45 degrees

Question 30

what are the different centering points for oblique foot

Answer 30

if all toes need to be included then centre at the 3rd metatarsal-phalangeal joint

for single toes, entered over metatarsi-phalangeal joint of individual toe

Question 31

what might occur if the foot is over rotated medially for oblique DP xray

Answer 31

toes will overlap

Question 32

what is tarsal coalition

Answer 32

2 bones grow into one another connected by a bridge of bone, cartilage or strong fibrous tissue

Question 33

what is pseudo-epiphysis

Answer 33

• epiphysis looking end of bone where an epiphysis is not normally located

e.g pseudo-epiphysis found at the distal end of the 1st metatarsal when the growth plate is actually found at the proximal end

Question 34

how can you tell the difference between a normal variant vs fracture

Answer 34

normal varient =
- smooth edge
- rounded
- found in characteristic locations
- non-symptomatci

fracture
- rough edges
- Lucent, linear or non-linear appearance
- symptomatic