The diagnostic accuracy of ultrasonography in determining the reduction success of distal radius fractures

Abstract

Objective: We evaluated the sensitivity and specificity of bedside ultrasound (US) for determining the success of reduction of displaced distal radius fractures. In addition, we determined the ability of US to diagnose causes of unsuccessful reduction.

Methods: In a prospective, double-blind fashion, patients over 18 of age whose acute distal radius fracture was to be reduced were approached for inclusion. The closed reductions were performed by orthopedics residents. Post-reduction, the fracture was checked by an Emergency Medicine (EM) resident by US. Ultrasound images were evaluated by an EM attending physician blinded to X-ray findings and post-reduction X-ray images were evaluated by an orthopedic surgeon blinded to the US findings.

Results: Sixty patients agreed to participate in the study. Of these, reduction was deemed successful by X-ray in 40 (66.7%). Of these 40, 39 (97.5%) were found to be successful reductions by US. In the 20 of 60 (33.3%) patients with unsuccessful reduction by X-ray, 19 (95%) were considered unsuccessful reductions by US. In evaluating the success of distal radius fracture reduction, compared to X-rays, US was 97.5% (95% CI 86.8 to 99.9) sensitive and 95% (95% CI 75.1 to 99.9) specific; its positive predictive value was 97.5% (95% CI 85.2 to 99.6) and negative predictive value 95% (95% CI 73.2 to 99.2).

Conclusions: Ultrasonography is highly sensitive and specific in determining the success of distal radius fracture reduction.

Keywords: Distal radius; Fracture; Reduction; Ultrasonography.

Figures

Fig. 1

Patient flow diagram.

Fig. 2

Performing of the ultrasonography from the dorsal (a) and lateral (b) of the distal radius and corresponding US images.

Fig. 3

Successful fracture reduction as seen on pre- and post-reduction X-ray and US images. A) Pre-reduction AP X-ray, B) Pre-reduction lateral X-ray, C) Pre-reduction fracture line by US (dorsal image), D) Pre-reduction fracture line by US (lateral image), E) Post-reduction AP X-ray, F) Post-reduction lateral X-ray, G) Post-reduction fracture line by US (dorsal image), H) Post-reduction fracture line by US (lateral image).

Fig. 4

Pre-and post-reduction X-ray and US images of a failed fracture reduction. A)Pre-reduction AP X-ray, B) Pre-reduction lateral X-ray, C) Pre-reduction fracture line by US (dorsal image), D) Pre-reduction fracture line by US (lateral image), E) Post-reduction AP X-ray, F) Post-reduction lateral X-ray,G) Post-reduction fracture line by US (dorsal image), H) Post-reduction fracture line by US (lateral image).

Fig. 5

X-ray and corresponding US images of a distal radius fracture. A) The fracture (yellow line) is angulated dorsally (X-ray), long axis of the distal radius (blue line) B) The fracture (yellow line) is angulated dorsally (US), bone cortex axis of the proximal of the fracture (blue line) C) The fracture (yellow line) is angulated towards the volar part (X-ray), long axis of the distal radius (blue line) D) The fracture line angulated towards the volar part (US), bone cortex axis of the proximal of the fracture (blue line) E) Multiple-fracture lines seen on the dorsal image (X-ray), F) Multiple-fracture lines seen on the dorsal image (US), G) Radial shortening (X-ray), H) Radial shortening (US) (lateral image).