Maximum metacarpal rotation and corresponding phalangeal correction were measured in 80 fingers of 40 cadaver hands. Total metacarpal rotation averaged 50° to 52° in the index, long, and ring fingers and 69° in the small finger. Phalangeal correction averaged 36° to 37° in the index, long, and ring fingers and 50° in the small finger (70% of rotation in the metacarpal). The orientation of the metacarpophalangeal joint was not a significant limiting factor. However, the deep transverse metacarpal ligament did limit maximum rotation at the metacarpal and the phalanx. The advantages of basal metacarpal osteotomy make this technique the procedure of choice for correcting malrotation of up to an average of 18° to 19° for the index, long, and ring fingers. For the small finger, 20° to 30° of correction is possible, depending on the direction of rotation. A table has been devised to predict the correction for individual digits.