Radiographic Interpretation of Distal Radius Fractures: Visual Estimations versus Digital Measuring Techniques

Abstract

Distal radius fractures are a common injury. In the emergency room, trainees regularly assess these fractures using visual estimation. Our hypothesis is that assessment of radiographic parameters has sufficient accuracy for rendering treatment consistent with formal measurements. This study compared visual measurements made by 25 orthopaedic residents and attending physicians to formal measurements made by a single fellowship trained musculoskeletal radiologist in a series of patients with distal radius fractures. A search was performed utilizing the ICD-9 code for distal radius fracture in all patients presenting to a single institution emergency department. Participants used visual estimation to rate 25 radiographs. Parameters estimated included radial inclination, radial height, volar tilt, and the presence of intra-articular displacement. Analysis using Lin concordance coefficients, Bland Altman plots, and the Kappa statistic evaluated the agreement between visual estimation and formal measurements. The proportion of raters whose estimates would have resulted in a course of treatment that conflicted with the formal reading quantified the potential impact of visual estimation on treatment. Concordance coefficients were poor for radial inclination (ρc = 0.13), radial height (ρc = 0.24), and volar tilt (ρc = 0.46). The Kappa statistic for intra-articular displacement was 0.4. Analysis performed according to level of training did not result in substantial improvements in these statistics. Treatment based on visual estimates conflicted with formal readings 34% of the time for radial inclination, 38% of the time for radial height, 27% of the time for volar tilt, and 31% of the time for intra-articular displacement. Visual estimation is not an adequate form of measurement for evaluation of patients with distal radius fractures. Physicians should be mindful of these results when developing treatment plans based solely upon visual estimation.