A reproducible method of measuring carpal height and carpal-ulnar
distance and expressing them as ratios of these distances to the length of
the third metacarpal, as reported in a previous paper9, was applied to
serial roentgenograms of seventeen patients with rheumatoid disease and six
patients with Kienbock's disease. These ratios provide an accurate
expression of the extent of carpal collapse and of ulnar translation.
However, once carpal collapse has occurred, the trajectory of hand motion
becomes flattened, and, as a result, the carpal height ratio will vary as
the wrist moves from maximum radial to maximum ulnar deviation. These
ratios may be of use in predicting a patient's clinical course, but a
larger clinical study is necessary before use of the measurements for this
purpose can be recommended with assurance.