Ankle xrays

1. An approach to
ankle x-rays
Aric Storck PGY2
(acknowledgement to Dr. Dave Dyck for several slides)
September 11, 2003

2. Objectives
Review basic ankle fracture classification
Review x-rays of common ankle
fractures
Discuss management of common ankle
fractures

3. Case 1:
25 year old female
•Jumped off roof
•Right ankle pain
•Inability to weight bear on right foot
What else do you want to know on
history and physical examination?
Does she need x-rays ?

4. Ottawa Ankle Rules:
Order ankle x-rays if acute trauma to ankle
and one or more of
•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%

5. You have decided to order an
“ankle x-ray.” The nurse entering
your orders asks which views you
want …

6. Ankle X-rays: 3 views
AP
•Identifies fractures of malleoli, distal tibia/fibula,
plafond, talar dome, body and lateral process of talus,
calcaneous
Mortise
•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

7. AP x-ray:
Identifies fractures of
•malleoli
•distal tibia/fibula
•plafond
•talar dome
•body and lateral
process of talus
•calcaneous

8. Tib/fib clear space Tib/fib overlap

9. AP xray

10. Now apply what
you’ve learned …
Lateral malleolar fracture
Tib/fib clear space <5mm
Tib/fib overlap >10 mm
No evidence of
syndesmotic injury

11. Mortise X-Ray
Taken with ankle in
15-25 degrees of
internal rotation
Useful in evaluation
of articular surface
between talar dome
and mortise

13. Mortise x-ray:
Medial clear space
•Between lateral border of
medial malleous and
medial talus
•<4mm is normal
•>4mm suggests lateral
shift of talus

14. Mortise x-ray:
Talar tilt
•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

15. Lateral x-ray:
Identifies fractures of
•Anterior/posterior tibial
margins
•Talus
•Displacement of talus
•Os trigonum

16. Stable vs Unstable
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

17. Walking the walk ….
Talking the talk
Ortho is on the phone. They
ask you to describe the
fracture….

18. Lauge-Hansen:
15 basic types of injury in 5 major
categories
•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

19. Danis-Weber
•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

20. AO classification:
Similar to Danis-Weber scheme
Takes into account damage to other
structures (usually medial malleolous)
~2 pages of classifications
•Remember them all for your exam!

21. AO classification

22. Pott’s classification:
Easy to remember
First degree
•unimalleolar
Second degree
•bimalleolar
Third degree
• trimalleolar

23. Case 2

25. Lateral Malleolar Fracture
Danis-Weber A
Mechanism
•Suppination/adduction (inversion)
Mortise intact
Stable fracture
Treatment
•Below knee cast

26. Case 3

27. Bimalleolar (lat & post malleoli)
Mechanism
•Inversion
•Avulsion of posterior
malleolus (post
tibiofibular ligament)
Medial mortise wide
•Suggests instability
Management
•Posterior slab
•Orthopedic consult
Source: McRae’s Practical Fracture Treatment

28. Case 4

30. Unstable
•Multiple ligamentous injuries
•Usually involves syndesmosis
Treatment
•Posterior slab
•Urgent orthopedic consultation
•ORIF
Trimalleolar Fractures

31. Source:Rosen
CASE 5

32. Fracture of distal tibial
metaphysis
•Often comminuted
•Often significant other injuries
Mechanism
•Axial load
•Position of foot determines injury
Treatment
•Unstable
•X-ray tib/fib & ankle
•Orthopedic consultation
Pilon (tibial plafond) fractures
Source:Rosen

33. Case 6

34. Tillaux Fracture
Occurs in 12-14 year olds
•18 month period when epiphysis is closing
Salter-Harris 3 injury
•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
•External rotation
•Strenth of tibiofibular ligament > unfused epiphysis

35. Tillaux Fracture
Management
•Inadequate reduction of articular surface can lead
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

36. Case 7
Source: Rosen

38. 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

39. Maisonneuve Fracture
Mechanism
•Eversion + lateral rotation
•Causes medial malleolar fracture or
deltoid ligament disruption

40. If injury proceeds along
syndesmosis it involves
proximal fibula = Maisonneuve
Fracture
Always rule out Maisonneuve
fracture in medial
malleolar/ligamentous injury

41. As talus continues to rotate
•Posterior tib-fib ligament ruptures
•Interosseous membrane rips
•Gross diastasis
•Dupuytren fracture –
dislocation of the ankle

42. Case 8

43. the end