When and how to image a suspected broken rib

Cleveland Clinic Journal of Medicine. 2009 May;76(5):309-314 | 10.3949/ccjm.76a.08026

May 1, 2009|Cleveland Clinic Journal of Medicine

Sharukh J. Bhavnagri, MD;Tan-Lucien H. Mohammed, MD

ABSTRACTRadiographic confirmation of rib fracture is often clinically irrelevant in patients who appear to have no complications or associated injuries. However, it is essential in a number of cases, especially when the clinical presentation and history raise suspicion of complications such as organ damage, or if the patient has other risk factors or conditions for which the precise information would help in management decisions. The authors discuss when to order imaging and which imaging test to order.

KEY POINTS

Knowing the number of ribs fractured may influence treatment decisions, such as whether to transfer a patient to a trauma center.
Classic clinical signs and symptoms of rib fracture include point tenderness, focally referred pain with general chest compression, splinting, bony crepitus, and ecchymosis.
In a patient with minor blunt trauma, when there is little suspicion of associated injury or complication, plain radiography is likely sufficient.
Computed tomography is the imaging study of choice in patients with penetrating or major chest or abdominal trauma.

Bone scan: Sensitive but not specific

Technetium Tc 99m methylene diphosphonate bone scanning can be used to look for bone pathology, including rib fractures. Bone scans are sensitive but not specific, and abnormal uptake generates an extensive differential diagnosis.¹⁶ Single-photon emission CT, or SPECT, can help localize the abnormality. ⁴ Because a hot spot on a bone scan can represent a number of conditions besides rib fractures, including cancer, focal sclerosis, and focal osteosclerosis, bone scanning is not routinely used for evaluating rib fractures, although it is very sensitive for stress fractures.

Occasionally, in a patient undergoing a bone scan as part of a workup for cancer, a scan shows a lesion that might be a rib fracture. In this case, one should correlate the results with those of plain radiography or CT.¹⁶

Magnetic resonance imaging: no role yet in rib fracture evaluation

MRI is not considered appropriate for evaluating rib fractures. It may be useful if there is concern about soft-tissue or vascular abnormalities. Beyond this, further research is needed to elucidate its role in rib fracture.

THE CHOICE OF TEST DEPENDS ON THE SITUATION

Figure 4. Recommended clinical management of patients with a history of chest trauma. In an asymptomatic patient, the key question is whether confirming a rib fracture with radiographic imaging will alter clinical management. In a symptomatic patient with a normal chest x-ray, one may consider CT to detect underlying injury as well as rib fractures.

Although several imaging tests can tell us if a patient has a rib fracture, in most cases the diagnosis of a rib fracture alone has little clinical relevance. The accurate and timely assessment of associated injuries and complications is more clinically useful, and for this, plain radiography and CT provide the most useful information. The choice of which test to use in a patient with a suspected rib fracture depends on the clinical circumstances (Figure 4).

In patients with penetrating or major chest or abdominal trauma, CT is the study of choice. It provides the most information about associated injuries, and it accurately detects rib fractures. This helps target treatment of associated injuries, and helps identify patients at higher risk, such as those with significant vascular, pulmonary, or abdominal injuries and those with a greater number of fractures. An unstable, critically injured patient would not be a candidate for CT because of the risk of transport to the scanner; chest radiography would have to suffice in these cases.

In cases of minor blunt trauma when there is little suspicion of associated injuries or complications, plain radiography is likely sufficient. If there is suspicion of a rib fracture alone and confirmation is of clinical importance (eg, in the elderly or those with long-standing refractory pain, or when certain pain management treatments are being considered), then oblique radiographic views, bone technique, and marker placement over the concerning region are recommended. The role of ultrasonography in this setting is still up for debate.

In cases of suspected rib fracture with longstanding pain refractory to conservative pain management, plain radiography with oblique views, bone technique, and marker placement is useful. If the radiograph is negative or if there is a high suspicion of cartilage fracture, CT or ultrasonography may be of benefit only if the diagnosis will alter clinical management.

If stress fracture is suspected, a nuclear bone scan may be helpful to first detect an abnormality, and CT may then be used for correlation if needed.

CASE CONCLUDED: LIVING WITH UNCERTAINTY

As for the 70-year-old man presented at the beginning of this article, the first question is whether we suspect an associated injury on the basis of clinical features. If we had clinical findings suspicious for pneumothorax or hemothorax, plain radiography of the chest would be indicated. Since the patient was not involved in major trauma, a CT scan is not indicated as the first study.

Our patient has clinical findings suggesting a rib fracture without associated injury. In this setting, routine posteroanterior and lateral chest radiography would be useful to rule out major associated injuries and, perhaps, to find a rib fracture. If the chest film is normal and rib fracture is still suspected, we must decide whether the diagnosis would alter our clinical management. Our patient would likely be treated the same regardless of whether or not he has a fracture; therefore, we would prescribe pain management.

Chest radiography was performed to rule out associated injuries, especially since the patient was elderly, but the chest x-ray did not reveal anything. On follow-up approximately 1 month later, he appeared improved, with less pain and tenderness. This may be due to healing of a rib fracture or healing of his soft-tissue injury. We will never know whether he truly had a fracture, but it is irrelevant to his care.

References

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