Pseudarthrosis (commonly referred to as a nonunion or false joint) is a bone fracture that has no chance of mending without intervention. In pseudarthrosis the body perceives bone fragments as separate bones and does not attempt to unite them. Often this is the result of inadequate healing after the fracture, though it can also be the result of a developmental failure. In the U.S., FDA guidelines allow a period of 9 months for fracture union, after which intervention is considered to facilitate union.