[A cineradiographic study of normal wrist motion].

To clarify carpal alignment during wrist motion, a cineradiographic analysis of 60 normal wrists was carried out. The radio-lunate angle, radio-scaphoid angle and scapho-lunate angle were all measured in lateral view. While in postero-anterior view, the angular change and radio-ulnar displacement of the lunate, and the height of the scaphoid were also measured. Normal standard curves for respective parameters were obtained from this analysis, which clarify the movement of each carpal bone. The normal standard curves enable the respective parameters of the X-ray films in the various positions to correct that in the neutral position. Therefore, the standard curves are useful not only for quantitative diagnosis of abnormality of the wrist joint, but for comparison of pre- and post-operative carpal alignment. Moreover, examination of variation and laterality among the individual normal cases confirmed the importance of examining movement patterns of the lunate in the diagnosis of carpal instability.