Ankle is a three bone joint
composed of the tibia ,
fibula an talus
Talus articulates with the
tibial plafond superiorly ,
posterior malleolus of the
tibia posteriorly and
medial malleolus medially
Lateral articulation is with
malleolus of fibula
The joint is considered saddle-shaped with the dome itself is wider
anteriorly than posteriorly, and as the ankle dorsiflexes, the fibula rotates
externally through the tibiofibular syndesmosis, to accommodate this
widened anterior surface of the talar dome
The tibiotalar articulation is considered to be highly congruent such that 1
mm talar shift within the mortise decreases the contact area by 42 %
MEDIAL SIDE LATERAL SIDE
LACINATE LIG.
TARSAL TUNNEL
ANTERIOR
SIDE
INTRODUCTION
Ankle fractures are among the most common injuries and
management of these fractures depends upon careful
identification of the extent of bony injury as well as soft tissue
and ligamentous damage.
Once defined, the key to successful outcome following
rotational ankle fractures is anatomic restoration and healing of
ankle mortise.
IMAGING AND DIAGNOSTIC MODALITIES
OTTAWA ANKLE RULES
To manage the large volume of ankle injuries of patients who
presented to emergency certain criteria has been established for
requiring ankle radiographs.
Pain exists near one or both of the malleoli PLUS one or more of the
following:
•Age > 55 yrs old
•Inability to bear weight
•Bone tenderness over the posterior edge or tip of either malleolus .
•Plain Films
–AP, Mortise, Lateral
views of the ankle
–Image the entire
tibia to knee joint
–Foot films when
tender to palpation
–Common
associated fractures
are:
•5th metatarsal
base fracture
•Calcaneal
fracture
Although the OTTAWA RULES have been validated and found to be both cost
effective and reliable (up to 100% sensitivity their implementation has been
inconsistent in general clinical practice
An initial evaluation of the radiograph should 1
st
focus on
•Tibiotalar articulation and access for fibular shortening
•Widening of joint space
•Malrotation of fibula
•Talar tilt
Identifies fractures
of
◦malleoli
◦distal tibia/fibula
◦plafond
◦talar dome
◦body and lateral
process of talus
◦calcaneous
On the anteroposterior view,
the distal tibia and fibula, including the
medial and lateral malleoli, are well
demonstrated .
important note is that the fibular
(lateral) malleolus is longer than the tibial
(medial) malleolus.
This anatomic feature, important for maintaining ankle stability, is crucial
for reconstruction of the fractured ankle joint. Even minimal displacement
or shortening of the lateral malleolus allows lateral talar shift to occur and
may cause incongruity in the ankle joint, possibly leading to posttraumatic
arthritis.
Quantitative analysis
◦Tibiofibular overlap
◦<10mm is abnormal - implies
syndesmotic injury
◦Tibiofibular clear space
◦>5mm is abnormal - implies
syndesmotic injury
◦Talar tiltTalar tilt
◦>2mm is considered abnormal
Consider a comparison with
radiographs of the normal side if there
are unresolved concerns of injury
Lateral malleolar fracture
Tib/fib clear space
<5mm
Tib/fib overlap >10 mm
No evidence of
syndesmotic injury
Taken with ankle in
15-25 degrees of
internal rotation
Useful in
evaluation of
articular surface
between talar
dome and mortise
10 degrees internal rotation of 5
th
MT with respect to a vertical line
Medial clear space
◦Between lateral border of
medial malleous and
medial talus
◦<4mm is normal
◦>4mm suggests lateral
shift of talus
•Abnormal findings:
–Medial joint space
widening
–Talocrural angle: <8
or >15 degrees
–Tibia/fibula
overlap:<1mm
Consider a comparison with
radiographs of the normal side if there
are unresolved concerns of injury
FIBULAR LENGTH: 1. Shenton’s Line of the ankle
2. The dime test
•Posterior mallelolar
fractures
•AP talar subluxation
•Distal fibular translation
&/or angulation
•Syndesmotic relationship
•Associated or occult
injuries
–Lateral process talus
–Posterior process talus
–Anterior process calcaneus
The ankle is a ring
◦Tibial plafond
◦Medial malleolus
◦Deltoid ligaments
◦calcaneous
◦Lateral collateral ligaments
◦Lateral malleolus
◦Syndesmosis
Fracture of single part
usually stable
Fracture > 1 part =
unstable
Source: Rosen
•Stress Views
–Gravity stress view
–Manual stress views
•CT
–Joint involvement
–Posterior malleolar fracture
pattern
–Pre-operative planning
–Evaluate hindfoot and
midfoot if needed
•MRI
–Ligament and tendon
injury
–Talar dome lesions
–Syndesmosis injuries
Some ligament injuries may be diagnosed on the basis of disruption of the ankle
mortise and displacement of the talus; others can be deduced from the
appearance of fractured bones.
For example,
fibular fracture above the level of the ankle joint indicates that the distal anterior
tibiofibular ligament is torn.
Fracture of the fibula above its anterior tubercle strongly suggests that the
tibiofibular syndesmosis is completely disrupted.
Fracture of the fibula above the level of the ankle joint without accompanying
fracture of the medial malleolus indicates rupture of the deltoid ligament.
Transverse fracture of the medial malleolus indicates that the deltoid
ligament is intact.
High fracture of the fibula associated with a fracture of the medial
malleolus or tear of the tibiofibular ligament, the so-called Maisonneuve
fracture (see later), indicates rupture of the interosseous membrane up to
the level of the fibular fracture
When radiographs of the ankle are normal,
however, stress views are extremely important in
evaluating ligament injuries .
Inversion (adduction) and anterior-draw stress
films are most frequently obtained; only rarely is
an eversion (abduction)-stress examination
required.
Inversion stress view. (A) For inversion
(adduction)-stress examination of the ankle, the
foot is fixed in the device while the patient is
supine. The pressure plate, positioned
approximately 2 cm above the ankle joint, applies
varus stress adducting the heel. (If the
examination is painful, 5 to 10 mL of 1%
Xylocaine or a similar local anesthetic is injected
at the site of maximum pain.) (B) On the
anteroposterior film, the degree of talar tilt is
measured by the angle formed by lines drawn
along the tibial plafond and the dome of the talus.
The contralateral ankle is subjected to the same
procedure for comparison.
This angle helps diagnose tears of the
lateral collateral ligament
The anterior-draw stress film, obtained in the lateral projection, provides a
useful measurement for determining injury to the anterior talofibular ligament
Values of up to 5 mm of
separation between the
talus and the distal tibia
are considered normal;
values between 5 and 10
mm may be normal or
abnormal, and the opposite
ankle should be stressed
for comparison. Values
above 10 mm always
indicate abnormality.
Radiography after reduction should be studied with
following requirements in mind:
•Normal relationship of ankle mortise must be restored.
•Weight bearing alignment of ankle must be at right angle to the
longitudinal axis of leg
•Counters of the articular surface must be as smooth as possible
Based on cadaveric study
•First word: position of foot at time of injury
•Second word: force applied to foot relative to
tibia at time of injury
Types:
Supination External Rotation
Supination Adduction
Pronation External Rotation
Pronation Abduction
•In each type there are several stages of injury
•Imperfect system:
–Not every fracture fits exactly into one category
–Even mechanismspecific pattern has been
questioned
–Inter and intraobserver variation not ideal
–Still useful and widely used
Remember the injury starts on the tight side of the ankle!
The lateral side is tight in supination, while the medial
side is tight in pronation.
Primary advantage :
Characteristic fibular # pattern
useful for reconstructing the mechanism of injury
a guide for the closed reduction
Sequential pattern – inference of ligament injuries
Disadvantages:
complicated, variable inter observer reliability
doesn’t signify prognosis
internal rotation injuries (Weber A3) missed
doesn’t indicate stability
1
23
4
Stage 1 Anterior
tibio- fibular
ligament
Stage 2 Fibula fx
Stage 3 Posterior
malleolus fx or
posterior tibio-
fibular ligament
Stage 4 Deltoid
ligament tear or
medial malleolus
fx
•Must x-ray knee to ankle to assess
injury
•Syndesmosis is disrupted in most cases
–Eponym: Maissoneuve Fracture
•Restore:
–Fibular length and rotation
–Ankle mortise
–Syndesmotic stability
Stage 1 Transverse
medial malleolus fx
distal to mortise
Stage 2 Posterior
malleolus fx or
posterior tibio-fibular
ligament
Stage 3 Fibula fracture,
typically proximal to
mortise, often with a
butterfly fragment
1
2 3
Medial injury: tranverse to short oblique medial malleolar fracture
Lateral Injury: comminuted impaction type distal lateral malleolar fracture
Based on location of fibula
fracture relative to mortise
and appearance
Weber A fibula distal to
mortise
Weber B fibula at level
of mortise
Weber C fibula
proximal to mortise
Concept - the higher the
fibula the more severe the
injury
Alpha-Numeric
Code
Tibia =4
Malleolar segment =4
Infrasyndesmotic=44A
Suprasyndesmotic=44C
Transsyndesmotic=44B
+
AO classification divides the three Danis Weber types further
for associated medial injuries.
•Maisonneuve Fracture
–Fracture of proximal fibula with
syndesmotic disruption
•Volkmann Fracture
–Fracture of tibial attachment of
PITFL
–Posterior malleolar fracture type
•Tillaux-Chaput Fracture
–Fracture of tibial attachment of
AITFL
Pott fracture.
In the Pott fracture, the fibula is
fractured above the intact distal
tibiofibular syndesmosis, the deltoid
ligament is ruptured, and the talus is
subluxed laterally
Dupuytren fracture.
(A) This fracture usually
occurs 2 to 7 cm above
the distal tibiofibular
syndesmosis, with
disruption of the medial
collateral ligament and,
typically, tear of the
syndesmosis leading to
ankle instability. (B) In
the low variant, the
fracture occurs more
distally and the
tibiofibular ligament
remains intact.
Wagstaffe-LeFort fracture.
In the Wagstaffe-LeFort
fracture, seen here
schematically on the
anteroposterior view, the
medial portion of the fibula is
avulsed at the insertion of the
anterior tibiofibular ligament.
The ligament, however,
remains intact.
•Collicular Fractures
–Avulsion fracture of distal
portion of medial malleolus
–Injury may continue and
rupture the deep deltoid
ligament
•Bosworth fracture
dislocation
–Fibular fracture with posterior
dislocation of proximal fibular
segment behind tibia
POSTERIOR COLLICULUS ANTERIOR COLLICULUS
INTERCOLLICULAR GROOVE
Tibial Pilon Fractures
The terms tibial plafond fracture, pilon fracture, and distal tibial
explosion fracture all have been used to describe intraarticular fractures
of the distal tibia.
These terms encompass a spectrum of skeletal injury ranging from
fractures caused by low-energy rotational forces to fractures caused by
high-energy axial compression forces arising from motor vehicle
accidents or falls from a height.
Rotational variants typically have a more favorable prognosis, whereas
high-energy fractures frequently are associated with open wounds or
severe, closed, soft-tissue trauma.
Source:Rosen
Rotational fracture of the ankle can be viewed as a continuum,
progressing from single malleolar fractures to bimalleolar fractures to
fractures involving the distal tibial articular surface.
Lauge-Hansen described a pronation-dorsiflexion injury that produces
an oblique medial malleolar fracture, a large anterior lip fracture, a
supraarticular fibular fracture, and a posterior tibial fracture.
Giachino and Hammond described a fracture caused by a combination
of external rotation, dorsiflexion, and abduction that consisted of an
oblique fracture of the medial malleolus and an anterolateral tibial
plafond fracture..
These fractures generally have little comminution, no significant
metaphyseal involvement, and minimal soft-tissue injury. They can be
treated similarly to other ankle fractures with internal fixation of the
fibula and lag screw fixation of the distal tibial articular surface through
limited surgical approaches
CLASSIFICATION OF ANKLE FRACTURES IN CHILDREN
Salter-Harris anatomic classification as applied to injuries of the distal
tibial epiphysis.
Classification of Ankle Fracture in Children (Dias-Tachdjian)
Supination Inversion
grade I adduction or inversion force avulses the distal fibular epiphysis
(Salter-Harris type I or II fracture). Occasionally, the fracture is
transepiphyseal; rarely, the lateral ligaments fail.
grade II further inversion produces a tibial fracture, usually a Salter-Harris
type III or IV and, rarely, a Salter-Harris type I or II injury, or the fracture
passes through the medial malleolus below the physis
B.Salter-Harris I fracture of the distal tibia
and fibula.
D. B. Salter-Harris I fracture of the fibula,
Salter-Harris II tibial fracture.
F.C. Salter-Harris I fibular fracture, Salter-
Harris III tibial fracture.
H.D. Salter-Harris I fibular fracture, Salter-
Harris IV tibial fracture.
Variants of grade II supination inversion injuries (Dias-Tachdjian
classification).
Supination Plantarflexion
The plantarflexion force displaces the epiphysis directly posteriorly,
resulting in a Salter-Harris type I or II fracture. Fibular fractures were not
reported with this mechanism. The tibial fracture usually is difficult to see
on anteroposterior x-rays
Supination External Rotation
In grade I the external rotation force results in a Salter-Harris type II
fracture of the distal tibia The distal fragment is displaced posteriorly, as in
a supination plantarflexion injury, but the Thurston-Holland fragment is
visible on an anteroposterior x-ray, with the fracture line extending
proximally and medially. Occasionally, the distal tibial epiphysis is rotated
but not displaced.
In grade II, with further external rotation, a spiral fracture of the fibula is
produced, running from anteroinferior to posterosuperior (
Pronation Eversion External Rotation
A Salter-Harris type I or II fracture of the distal tibia occurs
simultaneously with a transverse fibular fracture. The distal tibial
fragment is displaced laterally, and the Thurston-Holland fragment,
when present, is lateral or posterolateral . Less frequently, a
transepiphyseal fracture occurs through the medial malleolus (Salter
type II).