Point-of-care ultrasound useful for fracture diagnosis

Clinicians trained to use portable, point-of-care ultrasound equipment can achieve a high level of accuracy in identifying fractures in children and young adults when x-ray units are not available, according to a study published online in Injury.

Portable ultrasound potentially could be used to provide diagnostic imaging exams for injured patients in parts of the world without access to radiographic equipment. Fractures represent approximately 20% of emergency department visits by children for injuries, but treatment is often compromised because up to 75% of the world's population has no access to diagnostic imaging services, according to an estimate by the World Health Organization (WHO) (Injury, May 13, 2010).

Point-of-care ultrasound equipment is compact, portable, and less costly than x-ray systems. The modality is highly specific for identifying fractures as small as 1 mm due to the reflective acoustic properties of cortical bone. For this reason, pediatric emergency physicians at Bellevue Hospital Center in New York City conducted a study of patients younger than 25 who were admitted to the hospital's emergency department with suspected fractures. The prospective cohort study aimed to determine the accuracy of point-of-care ultrasound performed by clinicians.

Ten pediatric emergency physicians with varying levels of emergency ultrasound experience underwent one hour of point-of-care ultrasound training. The training combined the viewing of a 30-minute video with a 30-minute hands-on scanning session of normal bone anatomy and simulated fractures.

Lead author Eric Weinberg, MD, and colleagues reported that suspected fractures of the wrist and proximal foot were excluded due to the difficulty in evaluating intra-articular cortical surfaces and contours of these bones using ultrasound. Fractures were defined as cortical disruption or irregularity when scanning along the long axis of a bone, and as having a skipping or discontinuity effect when dynamically scanned along the short axis.

In all, 212 patients were enrolled in the study, of whom 67% were younger than 18 years. A typical ultrasound exam took four minutes. A single senior ultrasound technologist reviewed all of the ultrasound scans to provide quality assurance monitoring of the 348 bones that were imaged.

Bone fractures were accurately identified in 25% of the patients. Forty-three errors were made, all of which were attributable to operator technique; 37 involved ends of bones, with approximately one-third of these involving growth plates. Three false-negative sonograms were of a fractured clavicular shaft, a fractured phalanx shaft, and a fractured mandibular ramus. The two false-positive exams were of a rib and phalanx.

The authors reported an overall sensitivity of 73%, with 92% specificity. Sensitivity was 73% for long bones and 77% for nonlong bones, the latter representing 42% of the total. Specificity was 92% and 93%, respectively.

Radiographs remain the preferred diagnostic exam to identify or rule out bone fractures. However, the authors' data and the results of previously published studies suggest that point-of-care ultrasound may be an alternative for identifying fractures of the diaphyses of long bones, ribs, distal humerus, and skull, they wrote. In some cases, this might alleviate the need for radiation dose exposure where x-ray equipment is available.

In developing countries and geographically remote locations lacking x-ray equipment, point-of-care ultrasound by physicians minimally trained in its use may produce diagnostic images that can greatly benefit diagnosis. It also may be used in conjunction with satellite-delivered teleradiology for consultative interpretation, reflecting the origin of the first teleradiology services which provided clinical consultation to isolated villages in Canada and offshore drilling rigs in 1980.

By Cynthia E. Keen
AuntMinnie.com staff writer
July 7, 2010

Related Reading

SonoSite forms emergency services alliance, May 3, 2010

Nyaya Health brings ultrasound expertise to Nepal, June 25, 2009

Copyright © 2010 AuntMinnie.com

Page 1 of 507
Next Page