Ankle fracture

Background

Clinical Features

  • Examine for ecchymoses, abrasions, or swelling
  • vascular and neurologic assessment
    • DPs and PTs
    • 4 sensation distributions: saphenous nerve (medial mal), superficial fib (lat mal), sural nerve (lateral 5th digit), deep fib (1st web space)
  • 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

Differential Diagnosis

Other Ankle Injuries

Distal Leg Fractures

Foot and Toe Fractures

Hindfoot

Midfoot

Forefoot

Evaluation

Weber A Oblique
Weber B Oblique
Weber B AP
Weber C Oblique
Weber C AP
  • Ottawa Ankle Rules (sen 96-99% for excluding fracture)
  • 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 1 cm proximal to tibial plafond space between tib/fib should be ≤6mm
    • Lateral: Best for posterior malleolar fractures
  • consider proximal tib/fib films and talus fractures

Classification (Danis-Weber System)

WeberclassRadioped.jpg
  • system based on level of the fibular fracture and characterizes stability of fracture
  • tibial plafond and the two malleoli is referred to as the ankle "mortise" (or talar mortise)

Type A

  • fibula fracture below ankle joint/distal to plafond
    • medial malleolus often fractured
    • tibiofibular syndesmosis intact
    • usually stable: occasionally requires ORIF

Type B

  • fibula fracture at the level of the ankle joint/at the plafond
    • can extend superiorly and laterally up fibula
    • tibiofibular syndesmosis intact or only partially torn
    • no widening of the distal tibiofibular articulation
    • medial malleolus may be fracture
    • possible instability

Type C

  • fibula fracture above the level of the ankle joint/proximal to plafond
    • tibiofibular syndesmosis disrupted with widening of the distal tibiofibular articulation
    • medial malleolus fracture
    • unstable: requires ORIF

Management & Disposition

  • Determined by stability of fracture:
    • Stable, nondisplaced, isolated malleolar fracture: Splint or cast, early wt bearing, RICE
    • Unstable or displaced fracture: Requires ORIF, ortho consult, reduce and splint

Isolated lateral malleolar fracture

  • If stable (see Weber classification) treat like severe Ankle Sprain
  • Signs of instability:
    • Displacement >3mm
    • Associated medial malleolus fracture
    • Signs of medial (deltoid) ligament disruption such as medial swelling, ecchymosis, or TTP
    • Widening of medial clear space (suggests deltoid ligament injury)

Isolated medial or posterior malleolar fracture

  • Must rule-out other injuries
  • If non-displaced, isolated:

Lateral malleolar fracture with deltoid injury OR bimalleolar OR trimalleolar fracture

See Also

References

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