Ultrasound Case 021

Image 1: Longitudinal view of the 6th rib in the midaxillary line; The cortex of the rib is shown in its long axis. The site of maximal tenderness correlates with a non-displaced rib fracture. There is a small hypoechoic surrounding haematoma.

Rib fracture.

Visualising isolated rib fractures is not essential; management is usually symptomatic. The role of the clinician is to exclude more significant underlying injury and then advise regarding optimising analgesia whilst maintaining optimal lung function. Despite this I find patient and clinician satisfaction is increased if they can see their fracture.

Ultrasound can be used to visualise rib fractures and determine the degree of displacement – as well as determining the presence of associated pneumo- or haemothorax. Bones of the shoulder girdle (clavicle and scapula) obscure parts of the upper and posterior ribs.

Technique:

• Ask the patient to direct me to the site of the worst pain. Then find the rib most likely to be involved and using the linear probe view it in its long axis.
• Slide the transducer along the rib toward the sternum, and then back toward the spine. If a step in the cortex is seen a fracture is confirmed.
• Then explore the ribs above and below the site of maximal tenderness.

Pitfalls:

1. Novices frequently misidentify the costochondral junction as a fracture.
2. A slightly oblique view will show the cortex or the rib, then a step down to the echogenic pleural surface below. This has been misinterpreted as a displaced fracture.
3. As one proceeds following the rib posteriorly the angle of the rib has been erroneously labelled an angulated fracture.

Key Points: Correlate your findings clinically to ensure you interpret your images correctly!