Background: Effective methods of treating an unstable distal radial
fracture are described in the literature, but there is no reliable method of
identifying an unstable fracture in time to initiate appropriate treatment.
The purposes of this study were to identify the predictors of fracture
instability and to construct a method of prospectively predicting the
Methods: Data on approximately 4000 distal radial fractures were
prospectively recorded over a 5.5-year period. The database was validated by
reexamining a sample of it. Demographic data on the patients and mode of
injury, as well as the fracture classification and measurements, were recorded
at the time of presentation. Outcome measures consisted of radiographic
measurements made at one week and six weeks and assessment of carpal alignment
at six weeks. Univariate and multiple logistic regression analyses were
performed to identify the significance of the data obtained at presentation in
the prediction of early and late instability as well as the risk of malunion
and carpal malalignment.
Results: The predictors of early and late instability and malunion
differed according to the displacement of the fracture at presentation.
Patient age, metaphyseal comminution of the fracture, and ulnar variance were
the most consistent predictors of radiographic outcome. Dorsal angulation was
not found to be significant in the prediction of radiographic outcome for
displaced fractures. The degree to which the patient was independent was
predictive of malunion in minimally displaced and displaced fractures.
Formulas that are predictive of each of the seven radiographic outcome
measurements were constructed.
Conclusions: The study succeeded in identifying the factors that are
prognostic of the radiographic outcome for distal radial fractures. Formulas
to predict the radiographic outcome were constructed as the independent
prognostic significance of these factors was quantified. These formulas can be
used to inform the surgeon's decision about the nature of primary treatment of
fractures of the distal aspect of the radius. However, they must be validated
by further studies before they are used to impact the management of distal
Level of Evidence: Prognostic Level I. See Instructions
to Authors for a complete description of levels of evidence.