From the Guidelines
Assessment of ankle syndesmosis stability should be done using MRI as the reference standard for ligamentous injury and assessment of stability, particularly in athletes. The syndesmosis is the fibrous joint between the distal tibia and fibula, and its stability should be evaluated through a combination of clinical tests and imaging studies.
Clinical Examination
Begin with clinical examination using the squeeze test (compressing the fibula against the tibia at mid-calf level), the external rotation stress test, and the Cotton test (lateral-medial translation of the talus). Pain with these maneuvers suggests syndesmotic injury.
Radiographic Assessment
Radiographic assessment should include standard ankle views (AP, lateral, and mortise views) to evaluate for widening of the tibiofibular clear space (>6mm) or decreased tibiofibular overlap (<6mm) 1.
Advanced Imaging
Advanced imaging with MRI can directly visualize ligamentous damage, while weight-bearing CT scans provide the most accurate assessment of syndesmotic diastasis. Dynamic fluoroscopy during external rotation stress can reveal instability not apparent on static images 1.
Management
Unstable syndesmotic injuries typically require surgical fixation, while stable injuries may be managed conservatively with protected weight-bearing and rehabilitation. Proper assessment is essential because missed syndesmotic instability can lead to chronic ankle pain, instability, and premature osteoarthritis. Some key points to consider when assessing ankle syndesmosis stability include:
- The use of MRI to evaluate ligamentous integrity and assess stability 1
- The importance of clinical examination and radiographic assessment in evaluating syndesmotic injury 1
- The role of advanced imaging, such as weight-bearing CT scans and dynamic fluoroscopy, in assessing syndesmotic diastasis 1
- The need for proper assessment and management to prevent chronic ankle pain, instability, and premature osteoarthritis 1
From the Research
Assessing Ankle Syndesmosis Stability
- Ankle syndesmosis stability can be assessed through a combination of physical examination, imaging modalities, and clinical tests 2, 3, 4.
- Physical examination tests such as the external rotation test, proximal squeeze test, and fibular shuck test can assist in the diagnosis of syndesmotic instability 3.
- Imaging modalities including weight-bearing CT, ultrasonography, MRI, and arthroscopy can provide useful information in assessing syndesmotic instability 2, 3, 4.
- Clinical tests such as palpation, dorsiflexion lunge, squeeze test, and external rotation test have been studied for their diagnostic accuracy in assessing ligamentous injury of the ankle syndesmosis 5, 6.
- No individual test has been found to be associated with both high sensitivity and high specificity, highlighting the need for a combination of tests to confirm ankle syndesmosis involvement 5, 6.
- The squeeze test has been found to have high specificity, while tests such as palpation and dorsiflexion lunge have been found to have high sensitivity 5, 6.
- A combination of sensitive and specific signs, symptoms, and tests is recommended to confirm ankle syndesmosis involvement 6.
- Advanced imaging modalities and arthroscopy may be necessary to determine the extent of syndesmotic instability and to guide treatment decisions 2, 3, 4.