Tilted lateral radiographs in the evaluation of intra-articular distal radius fractures

The anatomy of the distal radius confounds the assessment of fracture displacement of the lunate facet. Since reduction of the articular surface is paramount to obtaining good clinical results, this study was designed to evaluate whether a radiograph taken 22 degrees from true lateral (forearm held at a 22 degrees angle from the horizontal film cassette) would enhance the accuracy of measuring displacement. Fifteen lunate facet fractures of varying depression were produced in 7 fresh cadaveric wrists. Posteroanterior (PA), standard lateral, and 22 degrees tilted lateral radiographs were obtained of each fracture pattern. Four observers reviewed the films and measured the depression of the fragments from their anatomic position. Measurement error from actual depression averaged 1.1 mm when the evaluators evaluated the 22 degrees lateral and PA films, 1.5 mm for the standard lateral and PA views, and 0.8 mm for the standard lateral, 22 degrees lateral, and PA radiographs (combined group). The decrease in measurement error obtained from all 3 groups was statistically significant. The results of this study suggest that the 22 degrees tilted lateral, either in combination with the standard lateral radiograph or just with the PA view, may help the hand surgeon better understand the intra-articular depression of lunate facet fractures of the distal radius.