Fracture non-union describes the failure of the normal fracture healing processes. Solid healing will not occur without further treatment intervention.
There is no consensus in the radiology or orthopedic literature, however, FDA defines it as a fracture with a minimum of at least nine months since the initial injury with no signs of healing for the final three months.
There are different types of fracture non-union with various imaging characteristics:
hypertrophic: abundant callus formation; radiolucent line (unmineralized fibrocartilage) at the nonunion site
oligotrophic: little or no callus formation; diastasis at the fracture site
atrophic: bony surfaces partially resorbed; no callus formation; osteopenia; sclerotic avascular bone segments; segmental bone loss
infected: osteolysis; osteopenia; sclerotic avascular bone segments; segmental bone loss
synovial pseudarthrosis: variable appearance (hypertrophic, oligotrophic, or atrophic)
- 1. United States Food and Drug Administration (USFDA), Office of Device Evaluation, Guidance Document for Industry and CDRH Staff for the Preparation of Investigational Device Exemptions and Premarket Approval Application for Bone Growth Stimulator Devices, 1988.