Marginal secondary displacement in fractures of the distal radius at follow-up - an important predictor for late displacement and malunion.

Treatment recommendations in fractures of the distal radius are often based on the degree of displacement and functional demands. The fracture may be within an acceptable radiological range, but a marginal deterioration in alignment then occurs between the initial visit and follow-up. This may pose a risk for late displacement that may require further treatment. We secondarily analysed prospectively collected data and included 165 patients. We found that marginal secondary displacement (odds ratio (OR) 9.7), anterior comminution (OR 8.8), loss of anterior apposition (OR 6.8) and dorsal comminution (OR 2.6) were predictors of late displacement. Marginal secondary displacement is an important predictor of late displacement and malunion in fractures of the distal radius. Clinicians should not unequivocally accept general guidelines on alignment but also assess a deterioration in fracture alignment on radiographic follow-up and be aware of the potential need for surgery to avoid malunion in cases that show early secondary displacement, even when radiographic measures are within acceptable limits. Level of evidence: III.