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

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.