captured with Casio digital camera (5 million pixels). The grey
level of X-ray films were analyzed by the Photoshop software
according to a imaging analysis method describe previously15. On
the anterior posterior (AP) view of the film, an area of 2.0×0.5
cm along the fracture line was selected, meanwhile, the mean
value of the grey level in the area was investigated by the order
of histogram. The selected area of initial film should be closed
to the proximal end of the fracture line, and this can reflect the
normal grey level of the bone and avoid the error from fracture site
overlapped. The selected area of the film after union was just on
the fracture line. The films were also assessed by three experienced
doctors who were blinded to the treatment method.