Prediction of instability of Colles' fractures.

The tendency of 267 consecutive Colles' fractures to dislocate during plaster-cast treatment was correlated with several parameters measured from the initial radiographs. Stepwise logistic regression analysis showed that radial axial shortening had the greatest prognostic power. The age of the patient and Lidström's class provided additional prognostic information. Initial radial axial shortening of 5 mm or more generally indicated an unfavorable anatomic end result.