Rare pantalar dislocations without associated talar or other fracture can be assessed on CT or MRI and have high rates of osteonecrosis, osteoarthritis, and infection [71]. MRI Ankle MRI is the reference standard for ligamentous injury and assessment of stability, which is particularly important in athletes, in whom determination of grade (1, 2, or 3) of syndesmotic ligament, anterior tibiofibular ligament, and deltoid injuries is critical for treatment planning and return to sport assessment [51]. Ligamentous injuries can occur without fracture on radiography. Grossterlinden et al [52] compared MRI and radiography and showed that 15% of ligamentous injuries (including sprains, partial tears, and complete tears) at the syndesmosis in acute ankle injuries on MRI demonstrated no fracture on radiography. Rare pantalar dislocations without associated talar or other fracture can be assessed on CT or MRI and have high rates of osteonecrosis, osteoarthritis, and infection [71]. Radiography Ankle Stress Views Stress radiographs may be useful in assessing syndesmotic instability, particularly in supination external rotation ankle injuries according to the Lauge-Hansen classification. Lee et al [72] noted that tibiotalar tilt angle and anterior tibiofibular space measurements were affected when the anterior tibiofibular and posterior talofibular ligaments were injured (confirmed on MRI) in 299 patients. Lateral stress testing with widening of the tibiofibular clear space has been shown to be an indicator of syndesmotic injury, with the traditional external rotation stress test shown to be a poor indicator when the deltoid ligament is injured [73]. Radiography Leg Maisonneuve fracture (syndesmotic injury of the ankle in combination with a proximal fibular fracture) may be overlooked as a result of lack of pain at the fibula. Careful palpation of the proximal fibula should be performed with radiographic evaluation of the entire tibia and fibular if focal tenderness is present [74].
Acute Trauma to the Ankle. Rare pantalar dislocations without associated talar or other fracture can be assessed on CT or MRI and have high rates of osteonecrosis, osteoarthritis, and infection [71]. MRI Ankle MRI is the reference standard for ligamentous injury and assessment of stability, which is particularly important in athletes, in whom determination of grade (1, 2, or 3) of syndesmotic ligament, anterior tibiofibular ligament, and deltoid injuries is critical for treatment planning and return to sport assessment [51]. Ligamentous injuries can occur without fracture on radiography. Grossterlinden et al [52] compared MRI and radiography and showed that 15% of ligamentous injuries (including sprains, partial tears, and complete tears) at the syndesmosis in acute ankle injuries on MRI demonstrated no fracture on radiography. Rare pantalar dislocations without associated talar or other fracture can be assessed on CT or MRI and have high rates of osteonecrosis, osteoarthritis, and infection [71]. Radiography Ankle Stress Views Stress radiographs may be useful in assessing syndesmotic instability, particularly in supination external rotation ankle injuries according to the Lauge-Hansen classification. Lee et al [72] noted that tibiotalar tilt angle and anterior tibiofibular space measurements were affected when the anterior tibiofibular and posterior talofibular ligaments were injured (confirmed on MRI) in 299 patients. Lateral stress testing with widening of the tibiofibular clear space has been shown to be an indicator of syndesmotic injury, with the traditional external rotation stress test shown to be a poor indicator when the deltoid ligament is injured [73]. Radiography Leg Maisonneuve fracture (syndesmotic injury of the ankle in combination with a proximal fibular fracture) may be overlooked as a result of lack of pain at the fibula. Careful palpation of the proximal fibula should be performed with radiographic evaluation of the entire tibia and fibular if focal tenderness is present [74].