A fracture nonunion is considered to be established when there are no visibly progressive signs of healing. Typically, fractured bone starts to heal after a fracture occurs or after a surgeon has re-aligned, reduced and/or set the fractured bone fragments back into alignment.
During the following weeks or months, new bone tissue forms and continues to grow. As long as the fractured bone fragments receive an adequate supply of blood and other bio-chemical induced nutrients, newly formed bone tissue will grow and fuse together into a solid remodeled, repaired bone. The majority of bone fractures heal normally.
A fracture nonunion is a serious medical complication and may occur when bone lacks adequate stability, weight bearing control, blood flow, or when there are other underlying medical conditions which impair normal healing.3