Accurate radiographic measurement of the distal radial tilt.

Both wrists in 189 patients who had been treated for dorsally displaced distal radius fracture were X-rayed with both right angle and 15° tilted lateral views. Two investigators measured the radial tilt. The mean difference in the angles recorded by the two investigators was 2.5° for the tilted and 3.7° for the right angle projections (p = 4.7 × 10(-8)). The precision of the method was 2.6° for the tilted and 3.5° for right angle projection. The mean angle measured on the tilted views was 3° more dorsal than on the right angle views for wrists with a volar tilt between 10° and 15°, and 0° to 2° for wrists with less volar tilt or dorsal displacement. Lateral projections tilted 15° allow more precise measurements than right angle views. Correction is not necessary when comparing to right angle views, as long as there is displacement in a dorsal direction of the distal fragment.