Ankle fracture

Physical Exam

  • Examine for ecchymoses, abrasions, or swelling
  • Note skin integrity and areas of tenderness or crepitus over ankle
  • Range joint passively and actively to evaluate for stability
  • Examine Joints above and below the ankle
  • Perform anterior drawer test (positive exam suggests torn ATFL)
  • Always palpate entire length of fibula to rule-out Maisonneuve Fracture (fibulotibialis ligament tear)
    • Perform a crossed-leg test to detect syndesmotic injury
  • Evaluate integrity of Achilles tendon (Thompson test)
  • Palpate midfoot and base of 5th metatarsal for tenderness

Diagnosis

  • Ottawa Ankle Rules
  • 3 views:
    • AP
      • Best for isolated lateral and medial malleolar fractures
    • Oblique (mortise)
      • Best for evaluating for unstable fracture or soft tissue injury
      • At a point 1cm proximal to tibial plafond space between tib/fib should be ≤6cm
    • Lateral
      • Best for posterior malleolar fractures
  • Determine if ankle fracture is:
    • Unimalleolar
    • Bimalleolar
    • Trimalleolar

Classification (Danis-Weber System)

System based on level of the fibular fx and characterizes stability of fx

Type A (supination-adduction injury)

  • Fibular Fx at or below level of ankle joint (talar mortise) without syndesmotic involvement
  • Typically stable
  • Deltoid ligament usually intact, medial malleolus usually fx
    • A1: isolated
    • A2: medial malleolus fx
    • A3: posteromedial fx

Type B (supination-external rotation injury)

  • Fibular Fx at level of ankle joint (talar mortise) w/ partial syndesmotic ligament injury
  • Stability dictated by integrity of tibiofibular syndesmosis (no widening of distal tibiofibular articulation)
  • Deltoid ligament may be torn, medial malleolus usually fx
    • B1: isolated
    • B2: medial lesion (either malleolus or ligament)
    • B3: medial lesion and fx of posterolateral tibia

Type C (pronation-eversion injury)

  • Fibular Fx above level of ankle joint (talar mortise) w/ complete syndesmotic disruption
  • Unstable (widened distal tibiofibular articulation) and require surgical correction
  • Deltoid ligament torn, medial malleolus fx
    • C1: simple diaphyseal fibular fracture
    • C2: complex diaphyseal fibular fracture
    • C3: proximal fracture
WeberclassRadioped.jpg


Management

  • Determined by stability of fx:
    • Stable, nondisplaced, isolated malleolar fx: Splint or cast, early wt bearing, RICE
    • Unstable or displaced fx: Requires ORIF, ortho consult, reduce and splint
  1. Isolated lateral malleolar Fx
    1. If stable (see Weber classification) treat like severe Ankle Sprain
    2. Signs of instability:
      1. Displacement >3mm
      2. Associated medial malleolus fx
      3. Signs of medial (deltoid) ligament disruption such as medial swelling, ecchymosis, or TTP
      4. Widening of medial clear space (suggest deltoid ligament injury)
  2. Isolated medial or posterior malleolar Fx
    1. Must rule-out other injuries
    2. If non-displaced, isolated:
      1. Short-Leg Posterior Splint (ankle at 90o)
      2. Non-weight bearing
      3. Refer in 5-7d
  3. Lateral malleolar fx with deltoid injury OR bimalleolar OR trimalleolar fx
    1. Short-Leg Posterior Splint (ankle at 90o)
    2. Immediate ortho consult in ED

X-rays

Weber A Oblique
Weber B Oblique
Weber B AP
Weber C Oblique
Weber C AP

See Also

Source

  • Tintinalli, Uptodate, Medpix Radiology Teaching Files (Images by Dr. Timothy Sanders),

http://radiopaedia.org/articles/weber_ankle_fracture_classification (Images by Dr. Frank Gaillard; CC SA NC BY licence),