Magnetic resonance arthrographic evaluation of syndesmotic diastasis in ankle fractures

We examined whether magnetic resonance arthrography (MRA) contributes to the diagnosis of syndesmotic complex disruption in ankle fractures. Patients suffering syndesmotic diastasis according to conventional radiographic criteria were evaluated by MRI and MRA.

Fifteen patients (15 ankles) with Denis-Weber type B and C fractures and were suspected of having syndesmotic diastasis considering tibiofibular clear space and tibiofibular overlap measurements in conventional radiographs were prospectively evaluated by MRI and MRA methods. Syndesmotic diastasis was diagnosed by radiographic, MRI, and MRA findings and by intraoperative observation and assessment criteria. Differences between MRI and MRA findings were tested statistically. Conventional radiography, MRI, and MRA results were analyzed by two independent observers, and interobserver concordance was also assessed.

In 15 patients regarded to have syndesmotic diastasis on conventional radiography the diagnosis was confirmed in 8 (53.3%) with MRI and 12 (80%) with MRA. Following overall assessment 13 of 15 patients (86.6%) were determined to have diastasis. There were statistically significant differences in diagnosis after MRI and after MRA. There was interobserver concordance in conventional radiographic, MRA assessments, and in assessments for anterior and posterior tibiofibular ligaments separately in MRI.

These results suggest that conventional radiography and MRI is not sufficient in assessing syndesmotic disruption, and that MRA can make an important contribution to diagnosis in ankle fractures.