Table 3

Criteria for assessment of a chronic unstable osseous ankle joint configuration: sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for different parameters and cutoff points

Cutoff criterionSensitivity %Specificity %PPV %NPV %
Tibiotalar sector4
 ≤80°56898367
 ≤81°60837867
 ≤82°75757575
 ≤83°79677176
 ≤84°83626878
 ≤85°87586781
froCu
 ≥1 mm9645150
 ≥2 mm74888676
TibCOR
 ≥1 mm85275464
 ≥2 mm67566063
 ≥3 mm52716460
 ≥4 mm33877156
  • froCu, depth of the frontal curvature of the talus; TibCOR, distance between the talar centre of rotation and the tibial axis.