Fig. 2

The measurement plane (plane Y) was selected individually. a The talus was hidden and the distal tibia articular surface was clicked to create a pseudo-straight plane as the tibial plafond (plane X). b “Point A” was selected on the anterior tubercle, which was defined as the intersection of the tangential along the anterior and posterior tubercle. c Selecting the measuring plane: the plane via point A paralleling the tibial plafond (plane X), called “plane Y”. The perpendicular distance from plane X to plane Y was measured