Rib fracture is the most common thoracic injury. It is found in 10% of all traumatic injuries and 40% of cases of blunt trauma.
5th to 9th ribs are most commonly involved probably due to the protection offered by shoulder girdle to upper ribs and mobility of lower ribs.
Isolated rib fractures have relatively low morbidity. But rib fractures should be watched for complications especially in severe injuries. These may include pneumothorax, hemothorax, pulmonary contusion, atelectasis, flail chest and visceral injuries.
Imaging of rib fractures is important to diagnose the rib fracture and its severity. American college of radiology has come out with imaging guidelines termed as American College of Radiology (ACR) Appropriateness Criteria for rib fracture.
Summary of the guideline and practical inference is mentioned below. For complete document, the link at the bottom may be followed.
No Dedicated Radiography for Minor Trauma
It is usually not necessary to perform dedicated radiography in addition to chest radiography for the diagnosis of in adults after minor trauma. CT or bone scintigraphy form dedicated studies.
Consider Dedicated Studies in Multiple Rib Fractures in Special Situations Only
There is no evidence that performing dedicated studies like CT, or bone scintigraphy are beneficial even in multiple fractures of ribs.
However, they should be considered such evaluation is necessary for establishing further care or other investigations. For example in cases of elder abuse, legal documentation etc.
Use of CT skeletal scintigraphy, and ultrasound in Occult Fractures and CPR survivors
These modalities may be helpful in evaluating selected patients with occult fractures [sterss fractures] and in evaluating selected CPR survivors or in situations in which identifying a rib fracture is deemed to be clinically important.
The standard posteroanterior (PA) chest radiograph is specific but not very sensitive for fractures. The supine anteroposterior [AP] radiograph is even less sensitive.
Clinical examination is sensitive but not specific.
Rib detail radiographs rarely add additional information to the PA film that would change treatment.
Dual-energy chest radiography with bone subtraction imaging has failed to show improved detection when compared with standard radiographs.
Multidetector CT provides an accurate assessment of fractures and associated internal injuries and is increasingly used as the method of choice for the radiologic evaluation of the trauma patient.
It also visualizes accurately cartilage fractures, which are typically missed on radiography.
However, CT is not usually performed only to evaluate for the presence of rib fractures.
Rather, it is used to evaluate for other associated complications of trauma.
Ultrasound (US) may also be used for depiction of rib fractures or associated costal cartilage injury in the emergency setting.
Bone scans are sensitive but not specific for detection of rib fracture. These are most commonly used for detection of bony involvement in systemic processes like metastatic disease and may result in a false-positive diagnosis of malignancy in a patient with rib fractures.
However, both could be differentiated on basis of the tracer uptake.