What is the recommended treatment for ligamentous (Non-Bony) syndesmotic fixation?

Treatment of Ligamentous (Non-Bony) Syndesmotic Injuries

For ligamentous syndesmotic injuries without associated fractures, surgical fixation is recommended for grade 3 (complete) tears, while grade 1 injuries should be managed conservatively with brief immobilization followed by functional rehabilitation, and grade 2 injuries require individualized assessment with a strong preference toward surgical intervention for optimal outcomes. 1

Initial Assessment and Grading

The severity of syndesmotic injury determines treatment approach 1:

• Grade 1 injuries involve partial ligament disruption with maintained stability 1
• Grade 2 injuries represent more extensive ligament damage with questionable stability 1
• Grade 3 injuries indicate complete ligamentous disruption requiring surgical intervention 1

Clinical examination should include external rotation and squeeze tests, which are reliable for detecting syndesmotic injury 2. The external rotation mechanism is the most common cause of these injuries, particularly in skiing, football, and soccer 2.

Conservative Management (Grade 1 Injuries)

For grade 1 syndesmotic injuries, immobilization should be limited to 1-3 weeks maximum, followed by immediate functional rehabilitation. 1

Key principles include:

• Immobilization duration must not exceed 10 days when possible to prevent joint stiffness and muscle atrophy 3
• NSAIDs may be used cautiously for pain control, recognizing they may suppress natural healing 3
• RICE alone is insufficient as a standalone treatment 3
• Functional support (brace or tape) is superior to simple compression bandages 3

Rehabilitation Protocol

• Begin exercise therapy immediately after the brief immobilization period to restore joint functionality 3
• Focus on proprioception, strength, coordination, and functional movements 3
• Supervised exercise-based programs are preferred over passive modalities 3
• Heel lift and posterior splint may prevent syndesmotic separation from excessive dorsiflexion 2

Critical pitfall: Avoid rigid external devices that compress the leg medial-laterally above the ankle mortise, as this can paradoxically induce syndesmotic separation 2.

Surgical Management (Grade 2 and 3 Injuries)

For grade 2 injuries, surgical treatment is strongly favored by the majority of practitioners, though stable grade 2 injuries may occasionally be managed conservatively. 1

For grade 3 injuries, surgical reconstruction is mandatory. 1

Surgical Fixation Options

Multiple fixation methods exist, each with distinct advantages 1, 4:

Screw Fixation (Most Common)

• 3.5-mm cortical screws engaging 4 cortices is the most prevalent approach (51% of surgeons use 3.5-mm screws, 67% engage 4 cortices) 4
• 4.5-mm cortical screws are used by 24% of surgeons 4
• Either 1 or 2 screws can be used (evenly split at 44% each in practice) 4
• Both tricortical and quadricortical fixation show similar strength and failure rates 5

Important consideration: Tricortical fixation shows a trend toward higher loss of reduction when weightbearing restrictions are not followed 5. Therefore, quadricortical fixation may be preferable when patient compliance is uncertain.

Alternative Fixation Methods

• Suture-button devices (TightRope, ZipTight) are used by 14% of surgeons and allow for physiologic motion 1, 4
• Fibular intramedullary nails are an option 1
• Bioabsorbable screws eliminate need for removal but have variable outcomes 1

Hardware Removal Considerations

Syndesmotic screws are routinely removed 65% of the time, typically at 3 months (49% of cases) in the operating room. 4

However, screw retention, even with mechanical failure, does not pose clinical problems 5. Screws should only be removed if symptomatic 5. This evidence suggests that routine removal may be unnecessary, though current practice patterns favor removal.

Postoperative Protocol

• Weightbearing can be allowed at 6-10 weeks without routine screw removal 5
• Early rigid immobilization for pain relief, followed by strengthening and balance training 2

Chronic or Missed Syndesmotic Injuries

For subacute or chronic injuries from missed diagnosis or failed conservative management 6:

• Arthroscopic debridement with screw fixation 6
• Tri-ligamentous reconstruction using minimally invasive techniques 6
• Anatomical reconstruction of anterior inferior tibiofibular, posterior inferior tibiofibular, and interosseous ligaments 6
• Arthroscopic guidance ensures anatomical reduction 6

Critical warning: The deltoid ligament plays a crucial role in maintaining syndesmotic stability and ankle mortise congruency 2. Always assess deltoid integrity, as combined injuries require more extensive reconstruction.

Key Clinical Pitfalls

• Prolonged immobilization beyond 10 days leads to joint stiffness and delayed recovery 3
• Premature return to activity risks re-injury and chronic instability 3
• Inadequate reduction results in chronic pain and progressive ankle degeneration 6
• Medial-lateral compression from external devices can worsen syndesmotic separation 2