Fracture of shaft of humerus is very amenable to treatment but a percentage of fractures do not heal. Normal healing of a humeral fracture occurs over 8 to 10 weeks. If the fracture has not achieved union by 3 to 4 months, it can be considered a delayed union. If union does not occur by 6 to 8 months it is called non union of the fracture.
Non unions are two types
Hypertrohic occurs due to increased vascularity which allows abundant callus to form. The callus formed has insufficient stability to prevents union.
In atrophic non unions, the fracture has inadequate blood supply and prevents callus.
Operative treatment methods have higher rate of non union as compared to non operative method. Apart from this there are various factors that increase the chance whether a patient would develop non union. These factors are
- Inadequate immobilization
- Distraction at the fracture site resulting in a gap between fractured surfaces
- Energy of the injury
- Open fractures
Treatment of the non union aims at removal of the cause if known, fixation of the fracture with surgery and bone grafting to augment the healing process.
The bone can be fixed by plating or intramedullary nailing. The graft is usually taken from iliac crest.
In caes of non union and osteoporosis, it might be difficult to attain the fixation. In such cases an additional procedure like filling he cabity with cement or augumentation with fibula may be needed