Mathematical analysis of computed carpal models.

The computed carpal models from digital computed tomography (CT) data obtained in this study compare favorably to natural anatomy. A new application of algebraic analysis of this data provides mathematical markers from which to calculate the position and orientation of each carpal bone. When the origin of the spatial coordinates of a carpal bone is transferred to the centroid of the bone, the data can be treated as three-dimensional pattern vectors describing its surface. It is then possible to calculate vectors that are the principal axes of the geometry. These axes provided references that were used to calculate position and orientation of the carpal bones in three wrist specimens. Comparisons of volumes, surface areas, and sizes and proportions of five computed images of each carpal bone from two of these wrists demonstrate the reliability of the technique. The analysis of CT scans of ceramics with known boundaries allows an estimation of its accuracy. The technique is well suited to the future study of normal wrist kinematics and pathological conditions.