Transcript Ankle Fractures

An approach to
ankle x-rays
Aric Storck PGY2
(acknowledgement to Dr. Dave Dyck for several slides)
September 11, 2003
Objectives

Review basic ankle fracture classification

Review x-rays of common ankle
fractures

Discuss management of common ankle
fractures
Case 1:
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25 year old female
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What else do you want to know on
history and physical examination?

Does she need x-rays ?
• Jumped off roof
• Right ankle pain
• Inability to weight bear on right foot
Ottawa Ankle Rules:
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Order ankle x-rays if acute trauma to ankle
and one or more of
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•
•
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Age 55 or older
Inability to weight bear both immediately and in ER (4
steps)
Bony tenderness over posterior distal 6 cm of lateral
or medial malleoli
Sensitivity ~100%
Specificity ~40%
You have decided to order an
“ankle x-ray.” The nurse entering
your orders asks which views you
want …
Ankle X-rays: 3 views
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AP
•
Identifies fractures of malleoli, distal tibia/fibula,
plafond, talar dome, body and lateral process of talus,
calcaneous
Mortise
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•
Ankle 15-25 degrees internal rotation
Evaluate articular surface between talar dome and
mortise
Lateral
•
Identifies fractures of anterior/posterior tibial margins,
talar neck, displacement of talus
AP x-ray:

Identifies fractures of
•
•
•
•
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malleoli
distal tibia/fibula
plafond
talar dome
body and lateral
process of talus
calcaneous
Tib/fib clear space
Tib/fib overlap
AP xray
Now apply what
you’ve learned …

Lateral malleolar fracture
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Tib/fib clear space <5mm
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Tib/fib overlap >10 mm
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No evidence of
syndesmotic injury
Mortise X-Ray


Taken with ankle in
15-25 degrees of
internal rotation
Useful in evaluation
of articular surface
between talar dome
and mortise
Mortise x-ray:

Medial clear space
•
•
•
Between lateral border of
medial malleous and
medial talus
<4mm is normal
>4mm suggests lateral
shift of talus
Mortise x-ray:

Talar tilt
•
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•
Normal = -1.5 to +1.5
degrees (ie. Parallel)
Can go up to 5
degrees in stress
views
<2mm difference
between medial and
lateral talar/plafond
distances
Lateral x-ray:

Identifies fractures of
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Anterior/posterior tibial
margins
Talus
Displacement of talus
Os trigonum
Stable vs Unstable
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Source: Rosen
The ankle is a ring
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Tibial plafond
Medial malleolus
Deltoid ligaments
calcaneous
Lateral collateral ligaments
Lateral malleolus
Syndesmosis
Fracture of single part usually
stable
Fracture > 1 part = unstable
Walking the walk ….
Talking the talk
Ortho is on the phone. They
ask you to describe the
fracture….
Lauge-Hansen:

15 basic types of injury in 5 major
categories
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•
•
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Described by two words
1. Position of foot at time of injury
2. Direction of talus within mortise causing fracture
Eg: supination-external rotation
Further subdivided into worsening areas of injury
Impossible to remember and clinically
useless in the ED
Danis-Weber
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Defines injury based on level of fibular fracture
• A=below tibiotalar joint
• No disruption of syndesmosis
• Usually stable
• B=at level of tibiotalar joint
• Partial disruption of syndesmosis
• C=above tibiotalar joint
• Disrupts syndesmosis to level of fracture
• unstable
THE MORE PROXIMAL THE FIBULAR # THE
MORE SEVERE THE INJURY
AO classification:

Similar to Danis-Weber scheme
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Takes into account damage to other
structures (usually medial malleolous)
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~2 pages of classifications
•
Remember them all for your exam!
AO classification
Pott’s classification:
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Easy to remember
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First degree
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Second degree
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Third degree
• unimalleolar
• bimalleolar
•
trimalleolar
Case 2
Lateral Malleolar Fracture
Danis-Weber A
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Mechanism

Mortise intact
Stable fracture
Treatment

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• Suppination/adduction (inversion)
• Below knee cast
Case 3
Bimalleolar (lat & post malleoli)
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Mechanism
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Inversion
Avulsion of posterior
malleolus (post
tibiofibular ligament)
Medial mortise wide
•
Suggests instability
Management
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Posterior slab
Orthopedic consult
Source: McRae’s Practical Fracture Treatment
Case 4
Trimalleolar Fractures
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Unstable
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Treatment
• Multiple ligamentous injuries
• Usually involves syndesmosis
• Posterior slab
• Urgent orthopedic consultation
• ORIF
CASE 5
Source:Rosen
Pilon (tibial plafond) fractures
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Fracture of distal tibial
metaphysis
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Source:Rosen
Often comminuted
Often significant other injuries
Mechanism
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Axial load
Position of foot determines injury
Treatment
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Unstable
X-ray tib/fib & ankle
Orthopedic consultation
Case 6
Tillaux Fracture
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Occurs in 12-14 year olds
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Salter-Harris 3 injury
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18 month period when epiphysis is closing
Runs through anterolateral physis until reaches fused part,
then extends inferiorly through epiphysis into joint
Visible if x-ray parallel to plane of fracture (may require
oblique)
Mechanism
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•
External rotation
Strenth of tibiofibular ligament > unfused epiphysis
Tillaux Fracture
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Management
• Inadequate reduction of articular surface can lead
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•
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to early OA
Gap >2mm in articular surface is unacceptable
Advanced imaging techniques may be necessary
Early orthopedic consultation
Non-displaced
• NWB below knee cast
• Displaced
• surgery
Case 7
Source: Rosen
Maisonneuve Fracture

Mechanism
• Eversion + lateral rotation
• May cause medial malleolar fracture or deltoid
•

ligament disruption
Injury proceeds along syndesmosis and
involves proximal fibula
Always rule out Maisonneuve fracture in
medial malleolar/ligamentous injury
Maisonneuve Fracture
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Mechanism
•
•
Eversion + lateral rotation
Causes medial malleolar fracture or
deltoid ligament disruption

If injury proceeds along
syndesmosis it involves
proximal fibula = Maisonneuve
Fracture

Always rule out Maisonneuve
fracture in medial
malleolar/ligamentous injury
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As talus continues to rotate
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Posterior tib-fib ligament ruptures
Interosseous membrane rips
Gross diastasis
Dupuytren fracture –
dislocation of the ankle
Case 8
the end