| Parameter |
Definition |
Normal value |
| Dorsal angulation (dorsal or volar or palmar tilt) |
Angle between a) the line which connects the most distal points of the dorsal and volar cortical rims of the radius and b) the line drawn perpendicular to the longitudinal axis of the radius. Side view of wrist with the forearm in neutral rotation. |
Palmar or volar tilt: approximately 11‐12 degrees. |
| Radial length |
Distance between a) a line drawn at the tip of the radial styloid process, perpendicular to the longitudinal axis of the radius and b) a second perpendicular line at the level of the distal articular surface of the ulnar head. Frontal view with the forearm in neutral rotation. |
Approximately 11‐12 mm. |
| Radial angle or radial inclination |
Angle between a) the line drawn from the tip of the radial styloid process to the ulnar corner of the articular surface of the distal end of the radius and b) the line drawn perpendicular to the longitudinal axis of the radius. Frontal view with the forearm in neutral rotation. |
Approximately 22‐23 degrees. |
| Ulnar variance |
Vertical distance between a) a line drawn parallel to the proximal surface of the lunate facet of the distal radius and b) a line parallel to the articular surface of the ulnar head. Frontal view with the forearm in neutral rotation |
Usually negative variance (e.g. ‐1 mm) or neutral variance. |
