Is a spiral fracture of the distal fibula typically non-weight bearing?

Management of Spiral Fractures of the Distal Fibula

Spiral fractures of the distal fibula typically require non-weight bearing initially, followed by progressive weight bearing based on fracture stability assessment and healing progress. Weight bearing status should be determined by evaluating medial clear space stability on weight-bearing radiographs.

Initial Assessment and Imaging

• Standard radiographs are the initial imaging of choice for distal fibula fractures 1

  • Three standard views are recommended: anteroposterior, lateral, and mortise views 1
  • Weight-bearing radiographs are preferred when possible, as they may detect dynamic abnormalities such as joint mal-alignment, joint subluxation, and fracture displacement that may not be apparent on non-weight-bearing radiographs 1
  • If weight-bearing is not feasible due to pain or risk of displacement, non-weight-bearing radiographs are an acceptable alternative 1

• Medial clear space (MCS) measurement is crucial for determining stability:

  • MCS < 4 mm indicates stability 2
  • MCS ≥ 4 mm indicates instability requiring surgical intervention 2

Weight Bearing Protocol Based on Fracture Stability

For Stable Fractures (MCS < 4 mm)

1. Initial management:

   • Non-weight bearing for 1 week with immobilization in a walking boot or cast 2
   • Follow-up with weight-bearing radiographs at 1 week to reassess stability 2

2. If stable on follow-up (MCS remains < 4 mm on weight-bearing radiographs):

   • Progressive weight bearing as tolerated in a functional walking boot 2
   • Continue immobilization for 3-4 weeks total 2

3. If unstable on follow-up (MCS ≥ 4 mm on weight-bearing radiographs):

   • Surgical fixation is indicated 2

For Unstable Fractures or Those Requiring Surgery

1. After surgical fixation with anatomically contoured locking plates:
   • Some evidence supports immediate full weight bearing 3
   • However, traditional protocols typically recommend:
     • Non-weight bearing for 2 weeks
     • Partial weight bearing for 2-4 weeks
     • Full weight bearing after 6 weeks

Rehabilitation Protocol

1. During immobilization period (typically 3-4 weeks):

   • Elevation to reduce swelling
   • Ice application during first 3-5 days for symptomatic relief

2. After immobilization:

   • Progressive range of motion exercises
   • Directed home exercise program to promote optimal recovery
   • Balance training and fall prevention exercises

3. Full recovery is typically expected within 6-8 weeks

Special Considerations

• Spiral fractures may have longer fracture lines than other fracture types, which can affect stability and healing time 4, 5
• Fracture displacement is a key factor in determining weight bearing status and need for surgical intervention
• Ankle stability is the most important criterion in treatment of malleolar fractures 1
• Surgical options for unstable fractures include:
  • Standard plating techniques
  • Double plating for problematic fractures requiring enhanced fixation 6
  • Contoured plates for better anatomic orientation in long spiral fractures 5

Common Pitfalls and Caveats

1. Failure to assess stability properly:

   • Weight-bearing radiographs are essential to determine true stability
   • Non-weight-bearing images may miss dynamic instability

2. Inadequate immobilization:

   • Even stable fractures require proper immobilization to prevent displacement

3. Premature weight bearing:

   • Can lead to displacement, malunion, and poor functional outcomes
   • Follow-up imaging is crucial before advancing weight bearing status

4. Missing associated injuries:

   • Carefully assess for syndesmotic injuries or medial ankle involvement

The evidence suggests that a careful assessment of fracture stability using weight-bearing radiographs can guide appropriate weight-bearing protocols, with stable isolated distal fibula fractures potentially allowing earlier weight bearing than traditionally prescribed.