AO basic course

1. AOTrauma Principles Course
Malleolar fractures
Peter PS KO, HK
Robert Vander Griend, US

2. Goal of this lecture
• Classification principles
• Patho-mechanics of injury
• Evaluation
• Treatment

3. Ankle fractures
• Intraarticular injuries
• Soft-tissue injury
- subcutaneous fracture
- soft tissues can be unforgiving

4. Ankle fractures
Injury: bone(s) and/or ligament(s)
1. medial malleolus—deltoid complex
2. lateral malleolus—lateral ligaments
3. anterior tubercle—anterior syndesmotic ligaments
4. posterior tubercle—post syndesmotic ligaments
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5. Classification: Danis-Weber (AO)
A fibula infrasyndesmotic
B fibula transsyndesmotic
C fibula suprasyndesmotic

6. Terminology used in Lauge-Hansen
classification
• Supination/pronation—position of foot as it rotates
around the subtalar joint
• Inversion (IR)/eversion (ER)—rotation of talus around
axis of tibia
• Adduction/abduction—rotation movements of talus
around its long axis

7. Classification: Lauge-Hansen
• Initial foot position
- supination vs pronation
→ tension failure
• Rotation of the talus
- transverse plane
(adduction vs abduction)
- external rotation to axis of tibia

8. Supination—Adduction/(A)
Lateral injury
• Ligamentous
• Avulsion fracture fibula
Medial injury
• Impaction fracture @ incisura!
• Vertical fracture medial malleolus
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9. Supination―External Rotation/ (B)
1. Anterior lateral ankle
2. Distal fibula
3. Posterior lateral ankle
4. Medial injury
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11. Pronation—Abduction (C1-2)
1. Medial injury
2. Disruption of inferior
syndesmosis
3. Axial/bending fracture of fibula
• Interosseous membrane injured
to the level of fibula fracture
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13. Pronation external rotation (C1 or C3)
1. Medial injury
1. Anterior syndesmosis
2. Rotational injury to fibula
3. ± posterior syndesmosis
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16. Assessment
• History
• Clinical examination
• Radiographic examination—AP, lateral, and mortise
views

17. Nonoperative treatment
• Nondisplaced fractures
• Stable fractures
• Patient or limb ≠ surgery
• Isolated lateral malleolus

18. Indications for surgery
• Failure of closed reduction
• Displaced fractures
• Unstable fractures

19. Preoperative planning
• Timing
- patient factors
- status of soft tissues

20. Preoperative planning
• Choice of implants
• Position of patient
• Approaches
• Sequence of reduction and fixation
• Pitfalls and hazards
• If you cannot plan it, you cannot do it

21. Patient position

22. Choice of incision
Sup.fibular nerve Saphenous nerve

23. Principles of fixation
• Medial malleolus
• Lateral malleolus
• Posterior malleolus
• Syndesmosis

24. Medial malleolus
• 4.0 mm distal, threaded cancellous bone screw
• perpendicular to fracture
• interfragmentary compression
tension band
small MM fragment
salvage

25. Medial malleolus
Vertically oriented fracture compression and buttress
Impaction fragment(s)

26. Lateral malleolus
• Anatomical reduction
- Length
- Rotation
- Mortise
• Fixation
- IFC & neutralization
- Bridging plate
- TSF
- IM ??
Case from R Teasdale

27. Lateral malleolus
Anti-glide
technique

28. Bimalleolar equivalent, SER 4, 44-B2.1
• Routine medial repair not needed
• Explore medial side if reduction not anatomical

29. Posterior malleolus
• > 25-30% of articular surface
• > 2 mm of displacement
• Posterior subluxation of talus
• To restore stability of syndesmosis

30. Transsyndesmotic fixation (TSF)
• Unstable syndesmosis
• Equivocal instability in “at risk” injury pattern
• Radiographic parameters
- medial clear space widened > 4 mm
- tib-fib clear space > 5 mm

31. Transsyndesmotic fixation (TSF)
• Intraoperative stress test
- hook or spreader
  mobility of fibula
- talar shift on external rotation stress films
• Equivocal?
- Nike test– “just do it”

32. Transsyndesmotic fixation (TSF)
• Ankle
• Fibula must be reduced
• Syndesmosis
• Holding screw(s) not
compression/lag screw
• Opinions vary use 1 or 2
screws, 3.5 mm vs 4.5 mm
screw, engage 3 or 4
cortices
• Remove TSF before WB
Image from Skeletal TraumaImage from Skeletal Trauma

33. After care
• Protected immobilization and elevation
- → Wound healed at 7–10 days
• Removable splint and early ROM
• Short leg cast
• Weight bearing based on injury pattern

34. Summary
• Intraarticular injuries (follow principles)
• Restore
- stability & congruency of joints
- normal function