President-elect Joe Biden fractured (broke a bone) his foot while playing with his dog on Saturday. X-rays did not show the fracture, but a CT scan did. It is being called a hair line fracture. This is a non-displaced fracture that occurs from an injury. A stress fracture occurs from repetitive overload activities. And a bone contusion is a bone bruise without a fracture. A hairline fracture is a specific injury such as a misstep or a rolled ankle causing a fracture that is not out of anatomical alignment. This fracture is often not seen on x rays for about 2 weeks until a bone callous can be seen. The hard-small bones of the midfoot that were injured are called the intermediate cuneiform (yellow) and lateral cuneiform (green). Treatment will likely be a surgical boot, ice anti-inflammatories and limited activity. He will likely be back to full activity in about 6-8 weeks.