Q

Why can't you see a stress fracture on x-ray?

Stress fractures are the result of repetitive microtrauma to a bone over time.  As this stress is placed on a bone over time, if the bone is weak or unable to recover from this repetitive load it can develop many minute cracks throughout the bone while not breaking it through-and-through.  These tiny cracks are not easily identified on x-rays as a typical fracture is because they are so small.  When taking an x-ray of a foot that has a suspected stress fracture, there are many other concerns and ailments we are ruling out and after the period of a few weeks we can see signs that a stress fracture is/was present.  As the bone heals a stress fracture, it lays down more bone to add strength.  Over the course of a few weeks, we can usually see this extra bony growth in the area of a stress fracture.  Depending upon where the stress fracture occured, this can be very obvious - but again, it take weeks before an x-ray will demonstrate the bony reparative process.

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