Normal Contralateral Variation of the Lisfranc Complex and Diagnostic Cutoffs for Subtle Instability Using 3D Weightbearing CT

In our study, we found a median physiologic difference of up to 12% between contralateral feet of healthy individuals. In the Lisfranc cohort, the median percentage difference was ≥32% across measurements; receiver operating characteristic analysis identified diagnostic cutoffs of 20% (volume), 26% (area), and 34% (diastasis). Therefore, measurements in the intermediate zone between 12% and 32% may warrant further assessment to prevent misdiagnosis and further morbidity. Between volume, area, and diastasis, diastasis showed the highest diagnostic performance (AUC = 0.90) for isolated Lisfranc instability.