What is the treatment for a non-displaced oblique distal fibular fracture at the level of the syndesmosis in a 33-year-old?

Treatment of Non-Displaced Oblique Distal Fibular Fracture at the Syndesmosis Level

For a 33-year-old with a non-displaced oblique distal fibular fracture at the syndesmotic level, conservative management with immobilization is the appropriate initial treatment, but syndesmotic stability must be rigorously assessed to determine if surgical fixation is required.

Initial Assessment: Syndesmotic Stability is Critical

The key decision point is whether syndesmotic instability exists, as this fundamentally changes management:

• Assess for syndesmotic injury clinically and radiographically - these injuries occur in 20-100% of ankle fractures and cannot be ruled out based on fracture pattern alone 1
• Measure the medial clear space - a distance <4mm confirms stability 2
• Obtain specialized radiographic views - standard AP and lateral views miss 54% of distal fibular avulsion fractures 2
• Consider dynamic stress radiographs if static imaging is equivocal, as static CT/MRI have high sensitivity but cannot define treatment strategy 1
• Ultrasound may be used adjunctively for assessment 1

Conservative Management (If Syndesmosis is Stable)

If the fracture is truly non-displaced AND the syndesmosis is stable:

• Immobilize for 1-3 weeks using a removable splint or cast 3
• Initiate immediate active toe motion exercises to prevent stiffness, which does not adversely affect adequately stabilized fractures 2
• Apply ice at 3 and 5 days post-injury for symptomatic relief 2
• Obtain radiographic follow-up at 3 weeks and at immobilization removal to confirm healing 2
• Partial weight-bearing (15-20 kg) for 6 weeks in an ankle-foot orthosis if treating conservatively 4
• Monitor for complications including skin irritation and muscle atrophy (occurs in 14.7% of immobilization cases) 2

Surgical Management (If Syndesmotic Instability Present)

The majority of grade 2 syndesmotic injuries and all grade 3 injuries require surgical treatment 3:

Indications for Surgery:

• Syndesmotic instability detected on dynamic testing 1
• Displacement >3mm, dorsal tilt >10°, or intra-articular involvement 2
• Fracture-dislocation (56% of suprasyndesmotic fibular fractures present with dislocation) 5
• Disruption of two or more syndesmotic ligaments 6

Surgical Technique:

• Anatomic reduction of the distal fibula into the tibial incisura is the single most important prognostic factor 6
• Restore fibular length, axis, and rotation - temporary pinning of the distal tibiofibular joint helps achieve proper fibular length 5
• Consider open reduction to ensure perfect reduction and avoid the most common complication of syndesmotic malreduction 6, 1

Fixation Options:

• Syndesmotic screws (metallic or bioabsorbable) placed 1.5-3cm from the talocrural joint 3, 1
• Dynamic button-suture fixation (TightRope or ZipTight) 3
• Minimally invasive intramedullary fibular nailing - results in significantly lower wound complications (union rates 97.4-100%) with comparable reduction quality to plating 4
• Refixation of bony syndesmotic avulsions if present 6

Critical Surgical Considerations:

• Use 1-2 syndesmotic screws in fracture-dislocations (needed in 72% of suprasyndesmotic fractures) 5
• Do NOT remove syndesmotic screws until fibular fracture shows healing - two patients developed occult diastasis after premature screw removal 5
• Average screw removal at 9 weeks if symptomatic 5
• Consider bone grafting in high-energy fractures with comminution 5

Common Pitfalls to Avoid

• Assuming stability based on "non-displaced" appearance - always formally assess syndesmotic integrity 1
• Early removal of syndesmotic hardware before fibular healing can lead to diastasis 5
• Accepting inadequate reduction - malreduction is the most frequent complication and leads to chronic instability, early osteoarthritis, and residual pain 6, 1
• Missing concomitant posterior malleolar fractures which strongly suggest syndesmotic injury 1

Expected Outcomes

• Conservative management of stable injuries: Good outcomes with gradual return to activity after 1-3 weeks 3
• Surgical management: 72% good results, 13% fair, 16% poor in complex suprasyndesmotic fractures 5
• Complications include: Nonunion (13%), delayed union (6%), deep infection (6%), and syndesmotic malreduction 5
• Poor results attributable to: Open fractures, infections, obesity, diabetes, noncompliance, and early hardware removal 5