[Diagnosis of torsion malposition of the radius and ulna after healed distal fracture].

Assessing radial and ulnar rotational deformities quantitatively by routine diagnosis after healed distal forearm fractures is very difficult. A method to obtain information about direction and graduation of malrotation is described. This method is based on discovering topographic changes of skeletal points by CT. Rotational angles of intact forearm bones are measured on anatomic specimen and in vivo using epiphyseal and diaphyseal axes of the radius and the ulna. Normal rotation of intact forearm bones varies in a specific manner. The radius presents less variations than the ulna. A morphological index of radial and ulnar rotation is not given because of the great individuality of diaphyseal rotation. Both radii of a single individuum show a very small rotational difference. Therefore a verification of malrotation is indicated by comparison to the intact opposite radius. Higher rotational graduations on the left side have to be noted.