The genetic profile of bone repair.

Bone repair following a fracture is a complex, well orchestrated, physiological process in response to injury. Even though the exact number of the genes and expressed proteins involved in fracture healing remains unknown, the molecular complexity of the repair process has been demonstrated, and it involves numerous genes and molecules, such as extracellular matrix genes, growth and differentiation factors, matrix metalloproteinases, angiogenic factors and others. Discrepancies in fracture healing responses and final outcome seen in the clinical practice may be attributed among other factors to biological variations between patients and different genetic "profiles", resulting in "altered" signalling pathways that regulate the bone repair process. Preliminary human studies support a "genetic" component in the pathophysiology of impaired bone repair seen in atrophic non-unions by correlating genetic variations of specific molecules regulating fracture healing with non-union. However, the role of the genetic "profile" of each individual in fracture healing and final outcome, and its possible interaction with other exogenous factors remains a topic of extensive research.