Comparison of pediatric post-reduction fluoroscopic- and ultrasound forearm fracture images

Abstract

Objective: Emergency department (ED) reduction of pediatric fractures occurs most commonly in the forearm and can be challenging if fluoroscopy is not available. We sought to assess the ability of point of-care ultrasonography (POCUS) to predict adequacy of reduction by fluoroscopy.

Methods: We prospectively enrolled ED patients 0-17 years of age with radial and/or ulnar fractures requiring reduction under fluoroscopic guidance. Post-reduction POCUS (probe dorsal, volar, and coronal) and fluoroscopic (AP and lateral) fracture images were recorded. Fracture angles were compared between blinded POCUS and fluoroscopic measurements and between POCUS measurements by a blinded emergency physician and a blinded radiologist, reporting mean differences and 95% confidence intervals. We calculated sensitivity, specificity, and likelihood ratios of POCUS in the prediction of fluoroscopically detected post-reduction malalignment, as interpreted by a blinded pediatric orthopaedist.

Results: The 58 patients were 7.9 ± 3.5 years of age and had 21 radial (36%), 1 ulnar (2%), and 36 radioulnar (62%) fractures. Fluoroscopy and POCUS angles were within a mean of 0.1°-3.2°, depending on the site and surface measured. Radiologist- and emergency physician-interpreted POCUS measurements were within a mean of 1° in all dimensions. POCUS identified inadequate reductions with 100% sensitivity and 92-93% specificity.

Conclusions: Blinded emergency medicine and radiology interpretations of post-reduction POCUS fracture images agree closely. Post-reduction POCUS measurements are comparable to those obtained by fluoroscopy and accurately predict adequacy of reduction. POCUS can be used to guide pediatric fracture reduction when bedside fluoroscopy is not available in the ED.

Keywords: Closed fracture reductions; Fluoroscopy; Forearm injuries; Fractures (radius and ulna); Pediatric emergency medicine; Ultrasonography.