How does callus show healing on non-displaced fractures?

Today's episode comes from a question on the Doc On The Run YouTube channel.  We were talking about how bone callus shows up as evidence of healing after a fracture in a runner.
 
Her question was:
 
“If there was no visible gap in between the bones where the fracture is, will the callus still be visible on the X-ray ? How will the callus show for non-displaced fractures on imaging? Thank you so much for creating this channel and for sharing all your expertise to the world.”
 
How does callus show healing on non-displaced fractures? 
 
Well, that's what we're talking about today on the Doc On The Run Podcast.