Bone, like any other tissue within the human body, is capable of healing itself when injured or damaged. When a fracture occurs, the body produces naturally occurring electric fields that generate high metabolic activity surrounding and within the bone that help to heal the fracture. Occasionally, the fracture may not heal normally on its own. This impaired ability to heal may result in what is called a fracture nonunion.
There are a number of underlying medical conditions and risk factors that may affect normal bone healing and result in a fracture nonunion. These include, but may not be limited to: chronic drug use, smoking, diabetes, obesity, chronic obstructive pulmonary disease (COPD), osteoporosis, renal disease, cancer, osteomyelitis (i.e., infection), rheumatoid arthritis and hypertension.
A fracture nonunion is considered to be established when there are no visibly progressive signs of healing. Usually, bone starts to heal immediately after a fracture occurs or after a surgeon has re-aligned and/or set the fractured bone fragments back into place.
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 and repaired bone. The majority of bone fractures heal normally.
A fracture nonunion is a serious medical complication and may occur when the bone lacks adequate stability, weight bearing control, blood flow, or when there are other underlying medical conditions which impair normal healing. 1