Comparison of ultrasound and plain radiography for the detection of long-bone fractures

Abstract

Objective: To compare emergency medicine (EM) resident physicians' ability to identify long-bone fractures using ultrasound (US) versus plain radiography (X-ray). Methods: This was an IRB-approved, randomized prospective study. Study participants included 40 EM residents at a single site. Fractures were mechanically induced in five chicken legs, and five legs were left unfractured. Chicken legs were imaged by both modalities. Participants were given 2 min to view each of the images. Participants were randomized to either US or X-ray interpretation first and randomized to viewing order within each arm. Participants documented the presence or absence of fracture and location and type of fracture when pertinent. Mean proportions and standard deviations (SDs) were analyzed using paired t-test and linear models. Results: Forty residents (15 postgraduate years (PGY)-1, 12 PGY-2, 13 PGY-3) participated in the study. Thirty-one participants were male, and 19 were randomized to US first. Residents completed a mean of 185 (SD 95.8) US scans before the study in a variety of applications. Accurate fracture identification had a higher mean proportion in the US arm than the X-ray arm, 0.89 (SD 0.11) versus 0.75 (SD 0.11), respectively (P < 0.001). There was no statistically significant difference in US arm and X-ray arm for endpoints of fracture location and type. Conclusion: EM residents were better able to identify fractures using US compared to X-ray, especially as level of US and ED experience increased. These results encourage the use of US for the assessment of isolated extremity injury, particularly when the injury is diaphyseal.

Keywords

• Diagnostics
• fracture
• ultrasound
• X-ray