Early and late displacement of fractures of the distal radius. The prediction of instability.

One hundred fractures of the distal radius with dorsal displacement were treated by closed reduction and a plaster cast. The mean age of the patients was 55 years. Radiographs were taken after 1, 2 and 5 weeks to evaluate the frequency of early and late displacement. Dorsal angulation occurred in 71 patients, shortening of the radius in 47 and flattening of the radial angle in 32. Late displacement was more frequent than early. Statistical analysis showed a greater incidence of secondary shortening in Older's types III and IV fractures. The severity of the initial radial shortening was the most reliable indication of instability.