Basic foot anatomy for ortho

1. FOOT Anatomy
FAILAGAO, NEL JOHN ROY B.
LEVEL 1 RESIDENT
WVMC

2. OSTEOLOGY
26 bones of the foot:
• 7 tarsal bones
• 5 metatarsals
• 14 phalanges
• Tarsals: includes talus, calcaneus, cuboid, navicular, and
three cuneiforms

3. Ossification
• Each tarsal bone has a single ossification center except for the
calcaneus
• Calcaneus, talus, and usually the cuboid are presentat birth
• Lateral cuneiform appears during the first year, the medial
cuneiform during the second year, and the
• Intermediate cuneiform and navicular during the third year
• The second through fifth metatarsals have two ossification centers
• Phalanges and first metatarsal have secondary centers at their
bases

4. • Hindfoot (talus and calcaneus),
• Midfoot (navicular, cuboid, and three cuneiforms)
• Forefoot (metatarsals and phalanges)

5. Talus
• Trochlea
• Two thirds of the talus is covered with cartilage
• Talar body wider anteriorly
• Talar neck connects with the head, which in turn
articulates with the navicular distally and the calcaneus
inferiorly
• Primary blood supply: Artery of the tarsal canal

6. Calcaneus
• Three surfaces that articulate with the talus
1. Posterior facet
2. Anterior facet
3. Middle facet
Distally, an articular surface receives the cuboid bone
* Sustentaculum tali

7. Cuboid
Four facets:
1. Calcaneus
2. Lateral cuneiform
3. Fourth metatarsals
4. Fifth metatarsals

8. Navicular
Most medial tarsal bone, the navicular lies between
the talus and the cuneiforms
• Proximally, the surface is oval and concave for its articulation with
the head of the talus.
• Distally, the navicular has three articular surfaces
• Medial plantar projection

9. Cuneiforms
Three bones (medial, intermediate, and lateral) Articulate with the
navicular and posterior cuboid (lateral cuneiform) and the first three
metatarsals
Intermediate cuneiform does not extend as far distally as the medial
cuneiform, which allows the second metatarsal to “key” into place.

10. Metatarsals
Five bones, numbered from a medial to lateral direction,
span the distance between the tarsal bones and phalanges.
Shape and function are similar to those of the metacarpals
of the hand
• First metatarsal has a plantar crista that articulates with
the fibular and tibial sesamoids contained within the flexor
hallucis brevis tendon.

11. Metatarsals
Note:
First metatarsal
• Shortest and widest
• Absorbs 50% of weight during the gait cycle
Second metatarsal
• Longest

12. Phalanges
• Similar to those of the hand.
• Great toe (analogous to thumb) has two phalanges, and
the remaining digits have three.

13. Arthrology
Distal tibiofibular joint: Formed by the medial distal fibula and the notched
lateral distal tibia
Ankle syndesmosis (connection between the tibia and fibula) supported
by four ligaments: anterior and posterior inferior tibiofibular ligaments, a
transverse tibiofibular ligament, and an interosseous ligament
• Anteroinferior tibiofibular ligament (AITFL) is an oblique band that
connects the bones anteriorly
• Tillaux fracture

14. Ankle joint
Ankle Joint Mortise
Deltoid ligament:
• Superficial layer (tibionavicular and tibiocalcaneal)
• Deep layer (anterior and posterior tibiotalar)
Lateral fibular ligaments:
• Anterior talofibular ligament (ATFL)
• Calcaneofibular ligament (CFL)
• Posterior talofibular ligament (PTFL)

15. Subtalar joint
• Talar plantar facets articulate with the calcaneus
Stability is derived from four ligaments:
1. Medial ligament
2. Lateral ligament
3. interosseous talocalcaneal ligament
4. cervical ligament
Plantar calcaneonavicular ligament (spring ligament)

16. Sprain Grading System

17. Arthrology
• Tarsometatarsal joint
• Lisfranc ligament
• Deep transverse metatarsal ligaments interconnect
metatarsal heads
• Plantar and collateral ligaments
• Plantar plate

21. ARCHES OF THE FOOT
• Support body weight
• Serves as a lever to propel the body forward in walking & running
1. A segmented structure can hold up weight only if it is built in the
form of arches
2. Weight will be distributed on:
A. the heel (behind)
B. heads of metatarsal bones (in front): pressure will be minimized on nerves &
vessels in sole
3. Forward propulsive action will be easier

22. Radiographic
examination

24. Calcaneus Fractures
• Calcaneus fractures account for approximately 2% of all
fractures.
• The calcaneus, or os calcis, is the most frequently fractured
tarsal bone

25. Anatomy

26. Radiographic Evaluation
• Standard Views:
1. Lateral
2. Harris Axial view (Os Calsis)
3. Broden’s view

27. Radiographic Evaluation
• Lateral View
–Loss of height of
the posterior facet
–Bohler’s angle:
20-40°
–Gissane’s angle:
95-105°

29. Radiographic Evaluation
• Harris axial heel view
– Foot in maximum
dorsiflexion
– Beam angled 45°
cephalad
– Shows subtalar joint
surface, loss of
height, increase in
width and
varus/valgus
angulation

31. Radiographic Evaluation
• Broden Views
– Supine, foot in neutral
flexion, internally
rotated 30-40°
– X-ray centered over
lateral malleolus,
taken at 40,30,20,10°
cephalad

32. CLASSIFICATIONS
• Most commonly used
─ Essex-Lopresti
─ Sanders

33. Essex-Lopresti Classification

34. SECONDARY FRACTURE LINE
• Tongue fracture: A secondary fracture line appears beneath the
facet and exits posteriorly through the tuberosity.
• Joint depression fracture: A secondary fracture line exits just
behind the posterior facet.

35. Essex-Lopresti Classification

36. Sanders’ Classification
• Based on number & location of articular
fragments on coronal view
• Posterior facet divided into 3 equal,
potential pieces (lateral, central, medial)
& sustentaculum tali

37. Sanders’ Type I
• All nondisplaced
fractures,
regardless of
number of pieces
• Usually non-
operative, unless
severely
displaced

38. Sanders’ Type II
• Two-part fracture
of the posterior
facet
• Subtypes IIA, IIB,
IIC
• Similar to a split
fracture of the
tibial plateau

39. Sanders’ Type III
• Three-part fractures
with a centrally
depressed fragment
• Subtypes IIIAB,
IIIAC, IIIBC
• Similar to a split,
depressed fracture
of the tibial plateau

40. Sanders’ Type IV
• Four-part, highly
comminuted
• Extremely difficult to
reduce the articular
surface
• Irreversible damage
to the “intact”
articular cartilage

41. CLASSIFICATION OF ARCHES
• A. Longitudinal
1. medial
2. lateral
• B. TRANSVERSE
1. ANTERIOR
2. POSTERIOR

42. MEDIAL LONGITUDINAL ARCH
Higher than lateral arch
Formed of: calcaneum, talus
(key stone), navicular, three
cuneiform & first three
metatarsal bones

43. Lower than medial arch
Formed of: calcaneum,
cuboid (key stone), fourth
& fifth metatarsal bones

44. TRANSVERSE ARCH
It is only half an arch
It is formed of: bases of
metatarsal bones, cuboid &
three cuneiform bones

45. FACTORS MAINTAINING ARCHES OF FOOT
• Shape of bones
• Strength of ligaments
• Tone of muscles

46. MECHANISM OF ARCH SUPPORT
SHAPE OF BONES
Bones are wedge-shaped with the thin edge lying inferiorly
This applies particularly to the bone occupying the center of the arch
“keystone”

47. MECHANISM OF ARCH SUPPORT
INFERIOR EDGES OF BONES ARE TIED
TOGETHER
Medial longtitudinal arch: plantar calcaneonavicular
ligament, tibialis posterior
Lateral longtitudinal arch: long & short plantar ligaments
Transverse arch: deep transverse ligaments, transverse
head of adductor hallucis, dorsal interossei

48. MECHANISM OF ARCH SUPPORT
TYING THE ENDS OF THE ARCH TOGETHER
• Medial longtitudinal arch: plantar aponeurosis, medial part of
flexor digitorum longus & brevis, flexor hallucis longus, flexor
hallucis brevis, abductor hallucis
• Lateral longtitudinal arch: plantar aponeurosis, lateral part of
flexor digitorum longus & brevis, abductor digiti minimi, flexor
digiti minimi
• Transverse arch: peroneus longus

49. MECHANISM OF ARCH SUPPORT
SUSPENDING THE ARCH FROM ABOVE
• Medial longtitudinal arch: tibialis anterior, tibialis posterior,
medial ligament of ankle joint
• Lateral longtitudinal arch: peroneus longus, peroneus brevis
• Transverse arch: peroneus longus

50. PES PLANUS (FLAT FOOT)
• A condition in which the medial longitudinal arch is depressed
• The forefoot is everted
• The head of talus is forced downward & medially
• The causes are both congenital and acquired

51. Plantar fascia
Plantar fascia (windlass mechanism)
• Origin: medial calcaneal tuberosity
• Insertion: base of the 5th metatarsal (lateral band), plantar
plate and bases of the five proximal phalanges
• Function: increase arch height as toes dorsiflex during
toe-off
• Major (2nd most important) medial arch support

56. Foot Loading
During Gait
1.2 times
: 2 times
5 times