Distal radius measurements: Lateral view

In a true lateral projection, the radius and ulna should be superimposed, and the pisiform projected over the distal pole of the scaphoid (white arrow). Normally, the lunate is seated within the fossa of the distal radius, and the curvature of their articular surfaces should correspond. Palmar migration is a sign of radiocarpal instability. Palmar tilt is the angle formed by the intersection of one line perpendicular to the longitudinal axis of the radial shaft and a second line drawn through the apices of the palmar and the dorsal rims of the radius. AP distance can also be measured.