Mechanical strength of intramedullary pinning and transfragmental Kirschner wire fixation for Colles' fractures

Four methods of distal radius fracture fixation were tested in this experimental biomechanical study of an unstable Colles' fracture model. Sixty artificial radial bones and seven pairs of cadaveric radii were used. Seven additional pairs of paired cadaveric radial epiphyses were used in separate perforation and cut-out tests. Tests with the artificial bones showed that the rigidity of the four tested fixation methods was comparable, except for proximal intramedullary pinning. The rigidity of the NODE fixation in the cadaveric radii was greater than that of transfragmental pinning. The load at failure was significantly greater for the NODE system than for the Kirschner wire models. Rigidity and failure loads showed a positive correlation with bone mineral density. The current study indicates the NODE system was the strongest of the fixation methods.