[Three-dimensional motion analysis of the wrist using two-directional radiography, with special reference to the...

To clarify the motion of the scaphoid, which exhibits unique movement among the carpal bones, three-dimensional motion analysis of the wrist was conducted. Three fresh-frozen cadavers were thawed, and three-dimensional measurement was carried out using two-directional radiography. Conventional two-dimensional measurement with unidirectional radiography was also carried out for comparison with the three-dimensional measurement. After measurement, the cadavers were dissected and the anatomical findings were correlated with results of measurement. During flexion-extension movement of the wrist, the scaphoid showed flexion-extension movement accompanied by rotation around the longitudinal axis. In radio-ulnar flexion of the wrist, the scaphoid did not exhibit flexion-extension movement in such a way as reported previously, but showed rotation around the longitudinal axis. These results and the anatomical findings suggest that the rotation around the longitudinal axis in both flexion-extension movement and radio-ulnar flexion is the movement along the articular surface of the capitate.