Transcript Slide 1

Anatomy of the Foot
Long Nguyen
Exam q’s
With which bones does the first (medial)
cuneiform articulate? How does the 1st
cuneiform appear in a lateral radiograph of
the tarsal region? (Oct 99)
 Give an account of the ossification centres
of the foot. State their time of appearance
and fusion. (?)
 What joints does the talus contribute to?
(?)
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Foot Bones
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Tarsus
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Proximal
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Medial
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Navicular
Distal
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Talus
Calcaneus
Medial, intermediate and
lateral cuneiforms
Cuboid
Metatarsals
Phalanges
Talus
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Only bone articulating with leg bones
No muscle attachments
Head articulates with navicular
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Inferiorly a has 3 facets
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Neck
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Directed inferiomedially making angle of 150º with body
Sulcus tali: deep groove which separates middle and
posterior talocalcaneal articular surface
Body
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Superior convex articular surface (trochlea) with
shallow central groove (saddle shaped)
Posteriorly
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Lateral tubercle: attachment for posterior talofibular
ligament
Medial tubercle: posterior fibres of deltoid ligament
Inferiorly
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Anterior talocalcaneal articular surface
Middle talocalcaneal articular surface
Facet for plantar calcaneonavicular (spring) ligament
Anterior talocalcaneal articular surface
Anastamotic blood supply running from anterior to
posterior. Fractures of talar neck can cause AVN of
body
Calcaneus
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Superior surface
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Roughened posterior 1/3
Middle 1/3: Posterior articular
surface for body of talus
Anterior 1/3: medial shelf-like
projection, sustentaculum tali
which has middle articular surface
for talus. Anteriolaterlly is the
anterior articular surface with
talus.
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Anterior surface articulates with
cuboid
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Posterior surface
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Smooth upper surface for
attachment of tendo calcaneus
Calcaneal tuberosity with lateral
and medial processes
Calcaneus
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Inferior surface
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Medial surface
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Anterior tubercle provides
attachment to short plantar
ligament
Sustentaculum tali projects
from anterior part of superior
border. Plantar
calcaneonavicular ligament
attaches in front and
superficial part of deltoid
ligament behind.
Lateral surface
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Flat except for peroneal
trochlea/tubercle
Calcaneus
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Superior surface
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Anterior surface articulates with cuboid
Posterior surface
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Anterior tubercle provides attachment to short plantar ligament
Medial surface
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Smooth upper surface for attachment of tendo calcaneus
Calcaneal tuberosity with lateral and medial processes
Inferior surface
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Roughened posterior 1/3
Middle 1/3: Posterior articular surface for body of talus
Anterior 1/3: medial shelf-like projection, sustentaculum tali which has middle
articular surface for talus. Anteriolaterlly is the anterior articular surface
Sustentaculum tali projects from anterior part of superior border. Plantar
calcaneonavicular ligament attaches in front and superficial part of deltoid
ligament behind.
Lateral surface
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Peroneal trochlea/tubercle
Calcaneus
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Subtle compression
fractures can be
suspected by
assessing Bohler’s
angle
If decreased below
25–40º, a fracture
should be suspected
Navicular and Cuboid
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Navicular
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Proximal: talus; plantar spring
ligament medially
Distal: 3 facets for cuneiforms
Lateral: cuboid
Medial: tuberosity for insertion
of tibialis posterior
Cuboid
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Proximal
Distal
Proximal: calcaneus
Distal: base of 4th and 5th MTs
Medial: lateral cuneform +/navicular
Lateral & plantar surface:
grooved by tendon of
peroneus longus
Inferior
Lateral
Cuneiforms
Wedge shaped
 Medial cuneiform (largest) broader at
plantar surface
 Intermediate & lateral cuneiform broader
at dorsal surface
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Metatarsals and phalanges
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MTs
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Base, shaft, head
Articulates with distal row of tarsus and
with each other
1st MT shortest and thickest
1st MT head has 2 articular facets on
plantar surface for two sesamoid bones in
tendon of flexor hallicus brevis
5th MT base has tuberosity on lateral
aspect providing attachment for peroneus
brevis tendon. Tuberosity may be avulsed
by acute inversion injury
Phalanges
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14 phalanges (2 in 1st digit)
Lisfranc injury
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Lisfranc’s joint is made up of
the tarsometatarsal joints and
a dislocation or fracturedislocation of this region is
termed a Lisfranc injury.
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The second MT base is held
by the strong plantar oblique
ligament between the medial
cuneiform and the second MT
base (Lisfranc ligament). This
is ruptured in a Lisfranc injury.
Ossification
Appearance
Union
Calcaneus
- posterior surface
5 month fetus
- 6-8 years
14-16 years
Talus
6 month fetus
Cuboid
9 month fetus
Lateral cuneiform
1 year
Intermediate
2 years
Medial
3 years
Navicular (several os
centres)
3 years
Ossification
Appearance
Union
MT shafts
9-10 week fetus
- epiphysis of 2-5 MT - 3-4 years
head, 1st MT base
Distal phalanges
- epiphysis at base
9-12 week fetus
- 6th year
Prox phalanges
- epiphysis at base
11-15 week fetus
- 2-8 years
Middle phalanges
- epiphysis at base
15+ week fetus
- 3-6 years
18 years
• MT & phalanges ossification centres appear by 2nd trimester of pregnancy
• Epiphyses appear by 6-8 years and fuse by 18 years
Sesamoid and accessory ossicles
(6) Os peroneum in
tendon of peroneus
longus (20%)
(7) Os vesalianum in
tendon of peroneus
brevis
(1) Os tibiale externum:
separate ossification
centre for tuberosity of
navicular (5%)
(12) Os trigonum:
separate ossification
centre for the posterior
surface of the talus
which does not unite
(1)
(6)
(7)
(12)
Tarsal coalition
Congenital fusion of tarsal bones
 Can be fibrous, cartilaginous or osseous
 Most common:
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Calcaneonavicular
 Talocalcaneal
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Joints of the hindfoot - Subtalar
joint
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Articulation between posterior
facet on the inferior surface
of the talus and the
corresponding surface of the
calcaneus
Reinforced by medial and
lateral talocalcaneal
ligaments and by interosseus
talocalcaneal ligament joining
the sulcus tali to sulcus
calcanei
Fibrous capsule lined by
synovium
Inversion and eversion of foot
Talocalcaneonavicular joint
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Articulation between head of
tarsus, posterior surface of
navicular anteriorly, the anterior
two facets on the superior
surface of the calcaneum and the
plantar calcaneonavicular
ligament
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Ball and socket type joint
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Ball: head of talus
Socket: two bones & two
ligaments
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Dorsal talonavicular ligament
(neck of talus to dorsal navicular
bone)
Plantar calcaneonavicular
(spring) ligament (sustentaculum
tali to posteroinferior surface of
navicular)
Calcaneocuboid joint
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Articulation between anterior
surface of calcaneum and
posterior surface of cuboid
Ligaments
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Dorsal calcaneocuboid ligament
Long plantar ligament (plantar
surface of calcaneus to cuboid
tuberosity)
Short plantar ligament (anterior
tubercle of calcaneus to adj plantar
surface of cuboid)
Transverse Tarsal (Midtarsal) Joint
= talocalcaneonavicular +
calcaneocuboid joint
Arches of the foot
Dorsum of foot
Sole of foot
4 muscular layers
 Maintain arches
 Muscles have gross functionality and are
of little importance individually
 Two neurovascular planes
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Superficial between 1st and 2nd layers
 Deep between 3rd and 4th layers
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Sole of foot – Layers 1 & 2
Sole of foot – Layers 3 & 4
Arterial supply