Control of the mechanical environment and alignment of a fracture is the primary goal of cast treatment for fractures. The same is true of the surgical treatment of new fractures using plates, screws or rods. Absence of infection Infection in a fracture site can occur in several settings. Bacteria can be introduced at the time of the fracture, if the skin over a fracture site is broken, or if the bone protruded though the skin. Both terms mean the same thing.
Infection can also be present prior to the fracture, in some settings.
In this case, the bone is often weakened by the infection, which then contributes as a cause of the fracture. Bacteria can also be introduced at the time of surgery in an otherwise uninfected fracture. In any case, if an infection occurs in a fracture site, healing of the bone is almost always inhibited or prevented, due to the destruction caused by the bacteria and other changes that the infection causes in the immune cells in the fracture site. Normal hormone function Bone cells and cells responsible for healing fractures to many hormone signals, such as growth hormone, parathyroid hormone, thyroid hormone, Vitamin D, among others. Rarely, an abnormality of one or more of these hormones can be identified as a likely cause contributing to the failure of bone healing.