Ankle Injury- Weber C

I think we all knew the last example in this series would be a Weber C - suprasyndesmotic injury.  So what's the trick?

Feeling pretty good on the medial malleolus.  What about the posterior malleolus?

Looks intact.  

Weber C / Pronation-Exorotation.  Low stage and stable right?  But wait....wasn't the medial mal OR medial supporting ligaments the first to fail in this mechanism?   

Aha! These are weightbearing films, what else can we do to test our medial structures.  (Callback!)

Nooooiicceee....ly unstable.  A whole bunch of stuff we can't always see radiographically has to happen for us to put enough tension on the fibular diaphysis for it to break above the syndesmosis - in this case, the medial supporting ligaments ruptured instead of the medial mal avulsing. Thinking about order and not just recognizing distribution will often have a payoff as well. 

More information on Weber classifications!

https://radiologyassistant.nl/musculoskeletal/ankle/weber-and-lauge-hansen-classification