Ultrasound as an aid to detect ankle and foot fractures
Although simple radiographs are used as a first approach in diagnosing fractures, avulsion fractures and occult fractures are easy to overlook.
Also, normal variants such as the growth plate in immature bones, accessory ossicles, secondary ossification centers, and canals or grooves for nutrient vessels are delineated as discontinuity of the bony surface and can mimic a fracture.
When simple radiographs show no evidence of a fracture, small avulsion or occult fractures can be seen on ultrasound (US).
US direct criteria for a fracture include:
- cortical discontinuity;
- a step-off deformity of the cortex;
- subperiosteal hematoma;
- a focal reverberation echo;
- overlying soft tissue edema;
- point tenderness on the fracture site;
- sometimes widening of the fracture space and movement of the bony fragments.
In addition, color Doppler US performed with dynamic scanning can more accurately and quickly detect fractures without radiation exposure.
A dynamic scan with color Doppler sonography can be a useful fracture diagnostic tool for point-of-care or primary care facilities without access to radiography.
> From: Oh et al., J Ultrasound Med (2017) (Epub ahead of print). All rights reserved to y the American Institute of Ultrasound in Medicine. Click here for the online summary.