What is the treatment for avulsion fractures of the distal fibular tip?

Treatment of Avulsion Fractures of the Distal Fibular Tip

For avulsion fractures of the distal fibular tip, conservative management with appropriate splinting is the recommended first-line treatment, as splints accommodate swelling better than casts and allow for skin inspection and hygiene. 1

Initial Management

• Splinting vs. Casting:

  • Splints are the optimal choice for acute avulsion fractures with anticipated swelling 1
  • Rigid immobilization with casts is preferred only for significantly displaced fractures 1
  • Splints provide better accommodation for swelling and allow for periodic skin inspection

• Immobilization Duration:

  • Average immobilization period: 3-4 weeks 1
  • Clinical and radiographic reassessment at 2-3 weeks to evaluate healing progression 1

Treatment Protocol

Phase 1 (0-2 weeks):

• Strict immobilization with splinting
• Weight-bearing as tolerated if lower extremity is involved
• Active finger/toe motion exercises to prevent stiffness 1
• Ice application during first 3-5 days for symptomatic relief 1
• NSAIDs for pain and inflammation control 1

Phase 2 (2-4 weeks):

• Continued immobilization
• Begin gentle range of motion exercises
• Clinical reassessment to evaluate healing

Phase 3 (4-6 weeks):

• Transition to normal footwear (if applicable)
• Progressive strengthening exercises
• Full recovery typically expected within 6-8 weeks 1

Special Considerations

Pediatric Patients

• Higher risk of recurrent ankle sprains with distal fibular avulsion fractures (44% vs 23% in those without fractures) 2
• Only 17% of pediatric avulsion fractures show radiographic union at 8 weeks 2
• Children have faster healing rates, potentially allowing for shorter immobilization periods 1
• Careful follow-up is essential due to increased risk of recurrent instability 2

Surgical Indications

• Persistent symptoms despite conservative management
• Significant displacement or large fragment size
• Presence of concomitant ankle instability 3
• Non-union leading to chronic ankle instability 4

Surgical Options

• Internal fixation with screws for larger fragments 4
• Modified Gould-Broström procedure for small fragments not amenable to fixation 4
• Surgical treatment of symptomatic os subfibulare (non-united avulsion fragment) generally results in substantial improvement with relatively low complication rates 3

Imaging Considerations

• Standard radiographs are the initial imaging of choice 1
• The anterior talofibular ligament (ATFL) view has significantly higher sensitivity (94%) for detecting avulsion fractures compared to standard anteroposterior and lateral views (46%) 2
• CT without IV contrast can better visualize fracture morphology in equivocal cases 1

Pitfalls and Caveats

• Excessive immobilization can lead to chronic pain, joint stiffness, muscle atrophy, and complex regional pain syndrome 1
• Inadequate immobilization can result in delayed healing, malunion, and progressive displacement 1
• Low-intensity pulsed ultrasonography (LIPUS) should NOT be used as it does not accelerate healing or lower rates of nonunion 1
• Non-union of avulsion fractures can lead to chronic ankle instability requiring surgical intervention 4
• Patient compliance with immobilization is crucial to prevent delayed healing 1