Functional anatomy of the ankle joint complex

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Functional Anatomy of
the Ankle Joint Complex
Professor Emeritus Moira O’Brien
FRCPI, FFSEM, FFSEM (UK), FTCD
Trinity College
Dublin

3. The Ankle Joint
•The ankle joint is one of the most common joints to
be injured.
•The foot is usually in the plantar flexed and inverted
position when the ankle is most commonly injured.
Bröstrom, 1966
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4. Tennis
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5. •Dorsiflexion and plantar
flexion take place at the
ankle joint
•In plantar flexion there
is some side-to-side
movement
Last, 1963
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The Ankle Joint
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6. Inversion and Eversion
•Initiated at the transverse
tarsal joint
•A radiological term
•Calcaneo-cuboid
•Anterior portion of the
talocalcaneonavicular
•Amputation at this joint,
no bones are cut
Last, 1963

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7. •Main movement take
place at the clinical
sub-talar joint i.e.:
•Talocalcaneal
•Inferior portion of the
talocalcaneonavicular
•The pivot is the ligament
of the neck of the talus
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Inversion and Eversion
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8. •A uniaxial, modified
synovial hinge joint
•Proximally the articulation
depends on the integrity of
the inferior tibiofibular joint
•Close pack
•Dorsiflexion
Williams & Warwick, 1980
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The Ankle Joint
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9. •In the anatomical position
the axis of the ankle joint
is horizontal
•But is set at 20-25º
obliquely to the frontal
plane
•Running posteriorly as it
passes laterally
Plastanga et al., 1990
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The Ankle Joint
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10. •In dorsiflexion the foot moves
upwards and medially
•Downwards and laterally in
plantar flexion
Plastanga et al., 1990
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The Ankle Joint
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11. Proximal Articular Surface
•The distal surface of the tibia
•which is concave antero-
posteriorly and convex from
side to side
•Medial malleolus (comma-
shaped facet)
•Lateral malleolus (triangular
facet is convex from above
downwards apex inferiorly
Williams & Warwick, 1980
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12. Proximal Articulation
•The inferior transverse tibiofibular
ligament
•Deepens it posteriorly
•Passes from the lower margin of
the tibia
•To the malleolar fossa of the fibula
Williams & Warwick, 1980
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13. •Proximally the articulation
depends on the integrity of
the inferior tibiofibular joint
•A syndesmosis
•Lateral malleolus is larger,
lies posteriorly
•Extends more inferiorly
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Proximal Articular Surface
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14. Distal Articular Surface
•The superior surface of the body
of the talus is wider anteriorly
•Convex from before backwards
•Concave from side to side
•Medial comma-shaped facet
•Lateral triangular facet
Frazer, 1965
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15. •The talus has no muscles
attached to it
•Has a very extensive articular
surface
•As a result fractures of the talus
may result in avascular necrosis
of either the body or the head
O’Brien et al., 2002
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Distal Articular Surface
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16. Posterior Aspect of Talus
•Two tubercles
•Groove contains flexor
hallucis longus
•Medial tubercle is smaller
•Lateral is larger, posterior
talofibular ligament attached
•7% separate ossification called os
trigonum
•There is a triangular facet on the
posterior surface which articulates with the inferior
transverse tibiofibular ligament
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17. Congenital Abnormalities
•Congenital abnormalities include
os trigonum and tarsal coalition
•Os trigonum in 7% of normal
population but in 32% of soccer
players
•It is a problem in soccer players,
ballet dancers and javelin
•Forced hyperplantar flexion
compresses the posterior portion
of the ankle and may fracture the
lateral tubercle or an os trigonum
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18. Articular Surfaces
•Articular surfaces are
covered with hyaline or
articular cartilage
•Synovial fold which may
contain fat
•Fills the interval between
tibia, fibula and inferior
transverse tibiofibular
ligament
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19. Capsule
•Is attached just beyond the
articular margin
•Except anterior-inferiorly
•Attached to the neck of the
talus
Williams & Warwick, 1980
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20. •The capsule is thin and weak
in front and behind
•The anterior and posterior
ligaments are thickenings of
the joint capsule
•The anterior runs obliquely
from the tibia to the neck of
the talus
Williams & Warwick,1980
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The Ankle Joint
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21. The Posterior Ligament
•The posterior ligament fibres pass
from: the tibia and fibula and
converge to be attached to the
medial tubercle of the talus
•Transverse ligament fibres form the
lower part of the posterior part of the
capsule, blend with the inferior
transverse ligament
•The posterior ligament is thicker
laterally
•Capsule is strengthened on either
side by the collateral ligaments
Williams & Warwick,1980
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22. The Medial (Deltoid) Ligament
•A strong triangular
ligament
•Superiorly attached
•The medial malleolus of
the tibia
Williams & Warwick, 1980
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23. Medial Ligament
•Inferiorly, ant-post
•The tuberosity of the
navicular
•Neck of talus
•The free edge of the
spring ligament
•The sustentaculum tali
•The body of the talus
Last, 1963
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24. Medial or Deltoid Ligament
(Superficial)
Crosses two joints
•Anterior tibionavicular
pass to the tuberosity of
the navicular
•The free edge of the
spring ligament
•The middle fibres, the
tibiocalcaneal are
attached to the
sustentaculum tali
Williams & Warwick, 1980
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25. Medial or Deltoid Ligament (Deep)

•The anterior tibio-talar to
the nonarticular part of the
medial surface of the talus
•The posterior tibiotalar to
the medial side of the talus
•The medial tubercle of the
talus
•Tibialis posterior and flexor
digitorum longus cross
ligament
Williams & Warwick, 1980
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26. Lateral Ligaments of Ankle
•The anterior talofibular
ligament
(ATFL)
•The calcaneofibular
(CFL)
•The posterior talofibular
(PTF)
•They radiate like the spokes
of a wheel
Liu & Jason, 1994
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27. The ATFL
•Is part of the capsule
•An upper and lower bands
•It is cylindrical, 6-10 mm
long and 2 mm thick
•The anterior inferior
border of the fibula runs
parallel to the long axis
of the talus when the
ankle is neutral or dorsiflexion
•More perpendicular to the talus when the foot is
equinus
Liu & Jason, 1994
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28. •It is the weakest ligament
•Strain increases with
increasing plantar flexion
and inversion
•The AFTL is a primary
stabiliser against inversion
and internal rotation for all
angles of plantar flexion
Liu & Jason, 1994
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The ATFL
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29. •The anterior draw tests
the ATFL
•Test should be done
with the ankle in 10
o
-20
o
plantar flexion
•Low loads
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Test for the ATFL
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30. •A long rounded 20-25 mm
long, 6-8 mm in diameter
•It contains the most
elastic tissue
•It is attached in front of
the apex of the fibular
malleolus
•Passes downwards and
backwards
•To a tubercle on the lateral aspect of the calcaneus
Williams & Warwick, 1980
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The CFL
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31. •It is separated from the
capsule by fibro-fatty tissue
•Part of the medial wall of the
peroneal tendon sheath
•Crosses both the ankle and
subtalar joints
•The CFL has the highest
linear elastic modulus of the
three ligaments
Siegler et al., 1988
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The CFL
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32. •When the ankle is in the neutral or
dorsiflexion, the CFL is
perpendicular to the long axis of the
talus
•Dorsiflexion and inversion result in
an increased strain
•Talar tilt tests the CFL
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The CFL
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33. The Lateral Ligament
•The angle between the
ATFL and CFL varies
between 100
o
and 135
o

•Increasing the potential
instability of the lateral
ligament
•The ATFL is the main talar
stabiliser and the CFL acts
as a secondary restraint
Hamilton, 1994; Peters, 1991
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34. ATFL and CFL
•A difference of 10
o
between the two ankles is
significant.
•A talar tilt of more than 10
o
is a lateral ligament injury in
99% of cases
•The AFTL is injured in 65% and combined injuries of
the AFTL and CFL occur in 20%
•The CFL is a major stabiliser of the subtalar joint

Liu & Jason, 1994
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35. The Posterior Talar Fibular (PTL)
•The PTL is the strongest part of
the lateral ligament
•It runs almost horizontally from
malleolar fossa to lateral
tubercle of talus
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36. •During plantar flexion the
posterior talofibular and the
posterior tibio fibular ligament are
edge to edge
•They separate during dorsiflexion
•The greatest strain on the
ligament is when the foot is
plantar flexed and everted

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The PTL
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37. •In 7% of normal population
the lateral tubercle has a
separate ossification and is
called an os trigonum
•It occurs in 32% of soccer
players
•Tarsal coalition is another
congenital abnormality
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The Ankle Joint
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38. Synovial Membrane
•Lines the capsule and the
non articular areas
•It is reflected on to the neck
•Extends upwards between
the tibia and fibula to the
interosseous ligament of the
inferior tibiofibular joint
•Covers the fatty pads that
lie in relation to the anterior
and posterior parts of the
capsule
Plastanga et al.,1980
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39. Ankle Stability
•The ankle is most stable in
dorsiflexion, with increasing
plantar flexion there is more
anterior talar translation
(drawer) and talar inversion
(tilt)
•The ATFL is the main talar
stabiliser and the CFL acts
as a secondary restraint
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40. •The tibiocalcaneal and the tibionavicular control
abduction of the talus
•The calcaneofibular controls adduction
•The anterior tibiotalar and the anterior talofibular
ligament control plantar flexion
•Posterior tibiotalar and the posterior talar fibular
ligament resist dorsiflexion
•Both the anterior tibiotalar and the tibionavicular
control external rotation and with the anterior
talofibular internal rotation of the talus
•The anterior talofibular is the primary stabilizer of
the ankle joint
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Ankle Stability
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41. Blood Supply of the Ankle
•Malleolar branches of the
anterior tibial
•Perforating peroneal and
posterior tibial arteries
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42. Nerve Supply of the Ankle
•Nerve supply is via articular
branches of the deep
peroneal
•Tibial nerve from L4 - S2
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43. Anterior Aspect
•Dorsi-flexors
•Tibialis anterior
•Extensor hallucis longus
•Anterior tibial becomes the
Dorsalis pedis artery
•Deep peroneal nerve
•Extensor digitorum longus
•Peroneus tertius
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44. •The medial branch of the
superficial peroneal nerve is
superficial to the retinaculum
•The long saphenous vein and
the saphenous nerve lie
anterior to the medial
malleolus
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Anterior Aspect
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45. Postero-Medial Aspect of the Ankle
•Tibialis posterior
•Flexor digitorum longus
•Posterior tibial vessels
•Posterior tibial nerve
•Flexor hallucis longus
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46. •The tibial nerve gives off the
medial calcaneal nerve then
divides into the medial and
lateral plantar nerves
•The medial calcaneal vessels
and nerve pierce the flexor
retinaculum to supply the skin of
the heel
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Postero-Medial Aspect of the Ankle
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47. Posterior Aspect
•Achilles tendon separated by
a bursa and pad of fat
•Posterolateral portal is lateral
to achilles tendon, sural nerve
and short saphenous vein at
risk
•Postero-medial not used;
flexor retinaculum structures
at risk
Jaivin & Ferkel, 1994
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48. Lateral Aspect of the Ankle
•The inferior extensor
retinaculum
•Extensor digitorum brevis
•Peroneus longus and
brevis
•Peroneal retinaculum
•Ligament of the neck of
talus
•Bifurcate ligament
•Sural nerve
•Short saphenous vein
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49. •Plantar flexion and
eversion
•Peroneus longus
•Peroneus brevis
•Dorsi-flexion and
eversion
•Peroneus tertius
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Lateral Aspect of the Ankle
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50. Nerves Related to Ankle Joint
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51. Tibialis Posterior
Superficial Peroneal Nerve
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52. Movements of Ankle joint
•Dorsiflexion is close
packed or stable position
•Wider portion of body of
talus between malleoli
•Range of 30
o
•Need 10
o
dorsiflexion to
run
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53. Dorsiflexion
•Dorsiflexion is produced by the tibialis
anterior
•Extensor hallucis longus
•Extensor digitorum longus
•The peroneus tertius
•Deep peroneal nerve
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54. Movements of Ankle joint
•Plantar flexion
•Some side to side
movement
•Narrow portion of body
between malleoli, 50-60
o
•Least pack, unstable
position
•Wide variation
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55. Plantar Flexion
•During plantar flexion
•The dorsal capsule
•The anterior fibres of the
deltoid
•The anterior talofibular
ligaments are under
maximum tension
•Plantar flexion is caused
mainly by the action of
the achilles tendon
•Assisted by the tibialis
posterior
•Flexor digitorum longus
•Flexor hallucis longus
•Peroneus longus and
brevis
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56. •The ankle is most stable
in dorsiflexion, with
increasing plantar flexion
there is more anterior talar
translation (drawer) and
talar inversion (tilt)
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The Ankle Joint
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57. Examination of Ankle
•ATFL
•CFL
•Distal tibiofibular
•Syndesmosis
•Deltoid ligament
•Lateral malleolus
•Medial malleolus
•Base 5
th
metatarsal
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58. •Achilles tendon
•Peroneal tendons
•Posterior tibial tendon
•Anterior process of calcaneus
•Talar dome
•Sinus tarsi
•Bifurcate ligament
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Examination of Ankle
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59. Ankle Examination
•Anterior drawer
•Talar tilt
•Inversion stress
•Squeeze test
•External rotation test
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60. Tests for Ankle Ligament Injury
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61. Ottawa Ankle Rules
•Anteroposterior
•Oblique
•Lateral views
•Bone tenderness
•Medial or lateral malleolus
•Unable to weight bear
•Four steps post injury
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62. A Few Statistics
•Basketball 5.5 ankle injuries/1000 player hours
•Netball 3.3 ankle injuries/1000 player hours
•Volleyball 2.6 ankle injuries/1000 player hours
•Soccer 2.0 ankle injuries/1000 player hours
Hopper et al., 1999
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63. Basketball Statistics
•53% of basketball injuries
are ankle injuries
•30.4 ankle injuries/1000
games
•10.0 ankle injuries/season
for a squad of twelve
Garrick, 1977
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64. Risk Factors
Extrinsic
• Training error
• Type of sport
• Playing time
• Level of competition
• Equipment
• Environmental
Intrinsic
• Malalignment
• Strength deficit
• Reduced ROM
• Joint instability
• Joint laxity
• Foot type
• Height/weight
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65. •Previous ankle injury Ekstrand & Gillquist, 1983; Milgrom et al., 1991
•Competition Ekstrand & Gillquist, 1983
•Muscle Imbalance Baumhauer et al., 1995
•Mass moment of inertia Milgrom et al., 1991
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Risk Factors
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66. Ankle Injuries
•Lateral ligament sprain
•Medial ligament sprain
•Peroneal dislocation
•Fractures
•Dislocations
•Tendon rupture
•Tibialis posterior
•Peroneal tendons
•Ruptured syndesmosis
•Superficial peroneal
nerve lesion
•Reflex sympathetic
dystrophy
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67. Ankle Sprains
•Grade one
Stretch of ATFL; mild swelling; no instability
•Grade two
Partial macroscopic tear; pain; swelling; mild-
moderate instability
•Grade three
Complete tear; severe swelling; unable to weight
bear; limited function; and instability
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68. Proprioception Theory
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69. Reducing Injury
•Proprioceptive
•Agility and Flexibility training Ekstrand & Gillquist, 1983
•Taping
•Loosens in 10 minutes Garrick, 1977
•Nil effect in 30 minutes? Tropp et al., 1985;
Rovere et al., 1988; Sitler et al., 1994
•Bracing
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