if the fracture was minor and "non-displaced" and the person did not have any subsequent injuries during this five-day period nothing will happen. if the bones are in good alignment all that may be needed is a cast. if the fractures are severe then there can be many complications from non-union (the bones not healing) to a compromise of the arm's blood supply. without seeing the xrays i would only have to blindly guess.
what results from not getting to a hospital for five days after breaking a radius and ulna