A method to determine the true angulation of long bone deformity.

A new method of geometrical analysis is capable of determining bone deformity from routine anteroposterior (AP) and lateral roentgenograms. The maximum angulation may occur in a plane other than the AP or lateral roentgenogram planes. Therefore, the maximum angulation may exceed the apparent angulation seen on routine AP and lateral views. The AP and lateral views will underestimate the true angulation most when the angulation seen on the AP and lateral views is similar.