What can cause aching pain a year after a metatarsal stress fracture?

This episode actually comes from a recent live Q&A I did with recovering injured runners and during these calls you can come on and you can ask me anything that you want about your specific situation. 
 
This was a really great question that came from one of the runners on the call and he was concerned about this discomfort he was getting in his foot a full year after he had a metatarsal stress fracture.
 
Today on the Doc On The Run Podcast, we're talking about what can cause aching pain in the top of the foot a year after a metatarsal stress fracture?