Interesting films of the week 2b

This injury usually catches people out when it is associated with an inversion ankle injury in the elderly (commonly stepping off a curb).

1.  What's the injury.
2. How is it "measured" on xray?
3.  What's the classical presentation?

1.  It's a calcaneal fracture - which can cause ankle pain as well as the more common heel pain, especially if it involves the anterior spine. 

2.  Learn to look for the Bohler's angle.  Normal is 30-40 degrees.  Less than 20 is pathognomic for a calcaneal fracture.  It's measured from the highest point at the back, to the high point at the middle, to the highest point at the front...

It's most commonly a fall from height such as jumping out of a window, hence it's other names - the Casanova, Don Juan or Lover's fracture.  But that doesn't need to be the case in osteoporotic patients, which is where most of these are missed. In the above photos you can also see how the posterior fat pad of the ankle on the right (nice crisp triangle) becomes enlarged and ragged in the presence of the fracture.

And remember the association with spinal fractures (7%) , especially at the thoraco-lumbar junction.....