10. Sesamoid bones
• Two in the tendon of FHB s at the
base of the metatarsophalangeal
joint of the hallux.
• Other MT joints and IP joints of 1st
and 2nd toes.
• Os trigonum posterior to the talus
• Os vesalianum at the base of the fifth
metatarsal
• Os peroneum between the cuboid
and the base of the fifth metatarsal
within the tendon of the peroneus
brevis muscle
• Os tibiale externum medial to the
tuberosity of the navicular within the
tendon of the tibialis posterior
muscle.
11. Ossification centres
• Lower end of tibia – sec centre appears at 2 years and fuses with shaft at
18 years.
• Lower end of fibula – sec centre in the first year and fuses at 16 years.
• Except for the calcaneus, the tarsal bones ossify from one centre each
– calcaneum and talus in the 6th fetal month
– cuboid at birth
– Cuneiforms and navicular at 1-3 years of age
• The secondary centre of the calcaneus ossifies in the posterior aspect of
the bone at 5 years and its density may be very irregular in the normal
foot. It fuses at puberty.
• Secondary ossification centres of metatarsals and phalanges appear by 3
yr and fuse by 18 year.
12. • On a lateral radiograph of
the foot in children over 5
years old, the long axis of
the talus points along the
shaft of the first
metatarsal.
• In the younger child the
talus is more vertical and
its long axis points below
the first metatarsal.
14. Ottawa ankle rules
• The Ottawa ankle rules are a clinical decision-
making strategy for determining which
patients require radiographic imaging for
ankle and foot injuries.
• Proper application has high (97.5%) sensitivity
and reduces the need for radiographs by
~35%.
18. Ankle joint
• Basic projections:
– Antero posterior
– Lateral (medio lateral)
– AP mortise
• Other projections:
– AP oblique
– AP stress
– AP weight bearing
19. AP PROJECTION
• Patient in supine/seated
position with the affected
limb fully extended.
• Flex the ankle and foot
enough to place the long
axis of the foot in the
vertical position.
• Central ray perpendicular
through the ankle joint at a
point midway between the
malleoli .
20. The following should be clearly
demonstrated:
•Tibio talar joint space
• Normal overlapping of the tibio
fibular articulation with the anterior
tubercle slightly superimposed over
the fibula
• Talus slightly overlapping the distal
fibula
• No overlapping of the medial talo -
malleolar articulation
• Medial and lateral malleoli
• Talus with proper density
• Soft tissue
21. LATERAL PROJECTION
Mediolateral
• With the ankle
dorsiflexed, the patient
turns on to the affected
side until the malleoli are
superimposed vertically
and the tibia is parallel to
the cassette.
• Centre over the medial
malleolus, with the
central ray at right-angles
to the axis of the tibia.
22. The following should be clearly
demonstrated:
• Tibiotalar joint well visualized,
with the medial and lateral talar
domes superimposed
• Fibula over the posterior half of
the tibia
• Distal tibia and fibula, talus, and
adjacent tarsals
• Density of the ankle sufficient
to see the outline of distal
portion of the fibula
23.
24. AP Mortise projection
• Center the patient's ankle joint to
the IR.
• Grasp the distal femur area with
one hand and the foot with the
other.
• Assist the patient by internally
rotating the entire leg and foot
together 15 to 20 degrees until
the inter malleolar plane is
parallel with the IR.
• CR perpendicular, entering the
ankle joint midway between the
malleoli.
25. The following should be clearly
demonstrated:
• Entire ankle mortise joint
• No overlap of the anterior
tubercle of the tibia and the
superolateral portion of the talus
with the fibula
• Talofibular joint space in profile
• Talus demonstrated with proper
density
29. AP stress projection
• Usually obtained after an
inversion or eversion injury
to verify the presence of a
ligamentous tear.
• Rupture of a ligament is
demonstrated by widening
of the joint space on the
side of the injury when,
without moving or rotating
the lower leg from the
supine position, the foot is
forcibly turned toward the
opposite side.
30.
31. AP projection
weight-bearing method
• performed to
identify ankle
joint space
narrowing with
weight bearing.
• Central ray is
perpendicular
to the center of
the cassette.
32. Foot
• Basic Projections:
– Antero posterior (Dorsi plantar)
– Antero posterior oblique
• Other Projections:
– Lateral
– AP oblique (lateral rotation)
– Lateral erect
– Dorsi plantar erect
33. AP/Dorsi plantar Projection
• Patient in the supine position.
• Flex the knee of the affected
side enough to rest the sole of
the foot firmly on the
radiographic table.
• The central ray is directed over
the base of third metatarsal.
• The X-ray tube is angled 10-15
degrees cranially when the
cassette is flat on the table.
34. The following should be clearly
demonstrated:
• No rotation of the foot
• Equal amount of space between
the adjacent midshafts of the
second through fourth
metatarsals
• Overlap of the second through
fifth metatarsal bases
• Visualization of the phalanges
and tarsals distal to the talus, as
well as the metatarsals
35. AP Oblique Projection
Medial rotation
• Rotate the patient's leg
medially until the
plantar surface of the
foot forms an angle of
30 degrees to the plane
of the IR.
• Central ray
perpendicular to the
base of the third
metatarsal.
36. The following should be clearly demonstrated:
• Third through fifth metatarsal bases free of
superimposition
• Lateral tarsals with Iess superimposition than
in the AP projection
• Lateral tarsometatarsal and intertarsal joints
• Sinus tarsi
• Tuberosity of the fifth metatarsal
• Bases of the first and second metatarsal
• Equal amount of space between the shafts of
the second through fifth metatarsals
• Sufficient density to demonstrate the
phalanges, metatarsals and tarsals
37. Lateral Projection
Mediolateral
• From the dorsi-plantar
position, the leg is rotated
outwards to bring the
lateral aspect of the foot in
contact with the cassette.
• Dorsiflex the foot to form a
90-degree angle with the
lower leg.
• Central ray perpendicular to
the base of the third
metatarsal.
38. The following should be clearly
demonstrated:
• Metatarsals nearly superimposed
• Distal leg
• Fibula overlapping the posterior
portion of the tibia
• Tibiotalar joint
• Sufficient density to demonstrate
the superimposed tarsals and
metatarsals
39. • used in addition to the routine
dorsi-planter projection to
locate a foreign body.
• It may also be used to
demonstrate a fracture or
dislocation of the tarsal bones,
or base of metatarsal fractures
or dislocation.
• Note : A metal marker placed
over the puncture site is
commonly used to aid
localization of the foreign
body.
40. Lateral erect
• demonstrate the
condition of the
longitudinal arches of
the foot, usually in pes
planus (flat feet).
• Both feet for
comparison.
41. Dorsi plantar erect
• performed to assess for a
dynamic widening of
the Lisfranc joint, which
would indicate a Lisfranc
injury
• Also used to show the
alignment of the
metatarsals and
phalanges in cases of
hallux valgus. Both
forefeet for comparison.
42. Calcaneus: Planto dorsal axial
• The affected leg is rotated
medially until both malleoli
are equidistant from the film.
• The ankle is dorsiflexed. The
position maintained by
bandage strap.
• Central ray is directed to the
midpoint of the IR at a
cephalic angle of 40 degrees
to the long axis of the foot.
The central ray enters the base
of the third metatarsal.
43. The following should be clearly
demonstrated:
• Calcaneus and subtalar joint.
• No rotation of the calcaneus-
the first or fifth metatarsals
not projected to the sides of
the foot.
• Anterior portion of the
calcaneus without excessive
density over the posterior
portion.
44. Calcaneus : Lateral Projection
Mediolateral
• The leg is rotated until
the medial and lateral
malleoli are
superimposed vertically.
• Centre 2.5 cm distal to
the medial malleolus,
with the vertical central
ray perpendicular to the
cassette.
45. The following should be clearly
demonstrated:
• No rotation of the calcaneus
• Density of the
sustentaculum tali, lateral
tuberosity, and soft tissue
• Sinus tarsi
• Ankle joint and adjacent
tarsals
46.
47. Sub talar joint: AP Axial Oblique Projection
Medial Rotation
• Also k/as Broden’s method.
• With patient's ankle joint maintained in
right-angle flexion, rotate the leg and
foot 45 degrees medially, and rest the
foot against a 45-degree foam wedge.
• Central ray angled cephalad at 40, 30,
20, and 10 degrees, respectively. Four
separate images are obtained.
• For each image, direct the central ray to
a point 2 or 3 cm caudoanteriorly to the
lateral malleolus, to the midpoint of an
imaginary line extending between the
most prominent point of the lateral
malleolus and the base of the fifth
metatarsal
48. • The anterior portion of
the posterior facet is
shown best in the 40-
degree projection.
• The 10-degree
projection shows the
posterior portion of the
posterior facet.
49. • The articulation
between the talus and
sustentaculum tali
(middle facet) is usually
shown best in one of the
intermediate projections
(20 and 30 degrees).
58. Measurements in lateral ankle view
• Heel pad measurement
• Achilles tendon
thickness
• Kager’s triangle
59. Kager’s triangle
• radiolucent triangle seen
posteriorly on lateral radiographs
of the ankle, represents the Kager
fat pad.
• bordered anteriorly by the flexor
hallucis longus (FHL) muscle and
tendon, posteriorly by
the Achilles tendon, and inferiorly
by the calcaneus.
• obliteration or distortion of its
borders are subtle indicators of
pathology involving the posterior
ankle.
61. Heel pad sign
• The heel pad should
normally be <21 mm in
female and <23 mm in
male.
• Increased in conditions
like:
– Acromegaly
– myxoedema
– callus formation
– phenytoin therapy
– obesity
– peripheral oedema
63. Tear drop sign
• sign of an ankle joint effusion.
• It represents the presence of
fluid in the inferior part of the
anterior compartment of
ankle.
• appreciated on a lateral
radiograph of ankle which is
seen as a teardrop-shaped
opacity that extends anteriorly
from the tibiotalar joint and
continues along the neck of
talus.
64. Böhler angle/Tuber angle
• angle between two lines tangent to
the calcaneus on the lateral radiograph.
These lines are drawn tangent to the anterior
and posterior aspects of the superior
calcaneus.
• normal value for this angle is between 20° to
40°.
• A value less than 20° can be seen in calcaneal
fracture. However, a normal Böhler angle
does not exclude a calcaneal fracture.
• Landmarks:
1= the most cephalic part of the posterior
process of the calcaneus bone
2= the most cephalic or highest point of the
posterior facet of calcaneus
3= the highest point of the calcaneus bone
that forms the articular surface for the
cuboid bone
65. Gissane’s angle
• also known as the crucial or critical
angle.
• angular measurement made directly
inferior to the lateral process of the
talus on lateral calcaneus view .
• formed by the downward and
upward slopes of the calcaneal
superior surface at the point of tarsal
sinus.
• normal value is usually between 120°
and 145°.
• An angle > 145° is concerning for
calcaneus fracture with involvement
of the posterior talar articular
surface .
66. • Gissane’s angle,
together with Böhler’s
angle, are commonly
used to evaluate the
severity of a calcaneal
fracture.
• The goal of a surgical
treatment is to restore
these angles to normal
values.
67. Angle of the longitudinal arch (foot)
• drawn on the weightbearing
lateral foot radiograph.
• between the calcaneal
inclination axis and a line
drawn along the inferior edge
of the 5th metatarsal.
• normal angle is 150-170°.
• Pes planus > 170 degree
• Pes cavus <150 degree
68. Tarsal coalition
• complete or partial union between two or more bones in
the midfoot and hindfoot.
• refers to developmental fusion rather than fusion that is acquired
secondary to conditions such as rheumatoid arthritis, trauma or
post-surgical.
• significant male predilection (M:F = 4:1) .
• 50% are bilateral (even if symptomatic only on one side).
• Pes planus (flat foot) is usually a feature.
• 90% calcaneo navicular and talo calcaneal coalition.
69. Talo calcaneal coalition
• C –sign > posterior
continuity of the talus
and sustentaculum tali
• Talar beak sign >
prominent beak at the
anterior aspect of the
talus
• Both signs better
appreciated on lateral x
ray.
70. Calcaneo navicular coalition
• Anteator nose sign -
anterior tubular
elongation of the
superior calcaneus
which approaches or
overlaps the navicular
on a lateral radiograph
of the foot
74. Trimalleolar fracture
• involves the medial
malleolus, the posterior
aspect of the tibial
plafond (referred to as
the posterior malleolus)
and the lateral malleolus .
• Having three parts, this is
a more unstable fracture
and may be associated
with ligamentous injury.
75. Pilon fracture
• Intraarticular distal
tibial fracture.
• result of an axial loading
injury which drives the
talus into the tibial
plafond, usually fall
from height.
76. Calcaneal fracture
• 60% of all tarsal
fractures; majority
intra-articular
• fall from height (Lover’s
fracture)
• Bohler’s angle < 20° and
Gissane’s angle > 145°
indicate fracture
77. Talar neck fracture
• most common fracture
of the talus
• forced dorsiflexion with
axial load
• high risk of avascular
necrosis and
degenerative arthritis
78. • Hawkins sign describes
subchondral lucency of the talar
dome that occurs secondary to
subchondral atrophy 6-8 weeks
after a talar neck fracture.
• It indicates that there is
sufficient vascularity in the talus,
and is therefore unlikely to
develop avascular necrosis later.
79. Chopart fracture
• fracture/dislocation of the mid-
tarsal joint (Chopart joint) of the
foot, i.e. talonavicular and
calcaneocuboid joints which
separate the hindfoot from
the midfoot.
• commonly fractured bones are
the calcaneus, cuboid
and navicular.
• foot is usually dislocated medially
and superiorly as it is plantarflexed
and inverted, usually as a result of
high energy impact, e.g. fall from
height or road traffic collision
80. Lisfranc injuries
• Lisfranc injuries, also
called Lisfranc fracture-
dislocations, are the most
common type of dislocation
involving the foot.
• correspond to the dislocation
of the articulation of the
tarsus with the metatarsal
bases.
• Injury mechanisms are varied
and include direct crush injury,
or an indirect load onto a
plantar flexed foot
81. Jones fracture
• transverse fracture at the
base of the fifth
metatarsal, 1.5 to 3 cm
distal to the proximal
tuberosity at the
metadiaphyseal junction,
without distal extension.
• In contrast to avulsion
fractures, Jones fractures
are prone to non-union.
82. Pseudo Jones fracture
• Avulsion fracture of the
5th metatarsal styloid, also known as
a pseudo-Jones fracture or adancer
fracture, is one of the more common
foot avulsion injuries.
• over 90% of fractures of the base of
the 5th metatarsal.
• Small fracture usually of the tip of the
proximal 5th metatarsal, oriented
mostly transversely .
• ascribed to the insertion of peroneus
brevis and is caused by forcible
inversion of the foot in plantar
flexion.
83.
84. References
• Anatomy for diagnostic imaging
• Merrills Atlas of Radiographic positioning
volume 1, 10th edition
• Clarke’s positioning in radiography
• https://radiopaedia.org/
At the age of 3 years, secondary ossification centres of the navicular, metatarsals and phalanges should all be present. The last secondary ossification centre to develop is the calcaneus appearing at 5 years.
Tangential projections for sessamoids.
Associated with spine and symphysis pubis fracture, if bilateral calcaneal fracture . haematoma along sole of foot (Mondor sign) .Sanders CT classification for intraarticular fractures.
