ADVERTISEMENT

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
Author and Disclosure Information

Sharukh J. Bhavnagri, MD
Imaging Institute, Cleveland Clinic

Tan-Lucien H. Mohammed, MD
Department of Diagnostic Radiology, Imaging Institute, Cleveland Clinic

Address: Tan-Lucien H. Mohammed, MD, Department of Diagnostic Radiology, Hb6, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195; e-mail mohammt@ccf.org

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.

HOW TO DIAGNOSE A BROKEN RIB

Signs and symptoms are unreliable but important

Clinical symptoms do not reliably tell us if a rib is broken.9,10 Nevertheless, the history and physical examination can uncover possible complications or associated injuries,10,11 such as flail chest, pneumothorax, or vascular injury.

Classic clinical signs and symptoms of rib fracture include point tenderness, focally referred pain with general chest compression, splinting, bony crepitus, and ecchymosis.9 A history of a motor vehicle accident (especially on a motorcycle) or other injury due to rapid deceleration, a fall from higher than 20 feet, a gunshot wound, assault, or a crushing injury would indicate a greater risk of complications.

Signs of complications may include decreased oxygen saturation, decreased or absent breath sounds, dullness or hyperresonance to percussion, tracheal deviation, hypotension, arrythmia, subcutaneous emphysema, neck vein distension, neck hematoma, a focal neurologic deficit below the clavicles or in the upper extremities, and flail chest.11 Flail chest results from multiple fractures in the same rib, so that a segment of chest wall does not contribute to breathing.

Further research is needed into the correlation of clinical symptoms with rib fractures. Much of the evidence that clinical symptoms correlate poorly with fractures comes from studies that used plain radiography to detect the fractures. However, ultrasonography and computed tomography (CT) can detect fractures that plain radiography cannot, and studies using these newer imaging tests may reveal a better correlation between clinical symptoms and rib fracture than previously thought.6

Chest radiography may miss 50% of rib fractures, but is still useful

Plain radiography of the chest with or without oblique views and optimized by the technologist for bony detail (“bone technique”) has historically been the imaging test of choice. However, it may miss up to 50% of fractures.10 Furthermore, it is not sensitive for costal cartilage3 or stress fractures.

Despite these limitations, plain radiography is vitally important in diagnosing complications and associated injuries such as a pneumothorax, hemothorax, pulmonary contusion, pneumomediastinum, or pneumoperitoneum. Also, a widened mediastinum could indicate aortic injury.

Currently, a standard chest x-ray is often the initial study of choice in the evaluation of chest pain and in cases of minor blunt trauma. If rib fractures are suspected clinically, a rib series can be of benefit. A rib series consists of a marker placed over the region of interest, oblique views, and optimization of the radiograph by the technologist to highlight bony detail. The decision to image a rib fracture in the absence of other underlying abnormalities or associated injuries depends on the clinical scenario.

Computed tomography provides more detail

Figure 2. Computed tomographic scan (zoomed axial image) shows an acute rib fracture.
CT is the primary study to fully evaluate for trauma-associated injuries and to evaluate bony detail (Figure 2). Its diagnostic capability is unsurpassed in this setting.11,12,13 It is also useful for diagnosing costal cartilage injury, whereas radiography is not.14 It can provide more details and new information when plain radiography indicates bone pathology: eg, a widened mediastinum suggesting vascular injury; pneumomediastinum or pneumoperitoneum of uncertain cause; cases of questionable pneumothorax; and locating foreign bodies or bony fragments, particularly in relation to vital vascular or nerve structures.

Figure 3. An axial image from a computed tomographic scan of the chest in a trauma patient shows a displaced fracture in a posterolateral right rib (arrow). There is an underlying effusion, the density of which indicates hemothorax. There is also a pulmonary contusion.
Additionally, CT may help elucidate nonspecific findings such as lung opacification, which may represent hemothorax or pulmonary contusion or both (Figure 3). It can also better characterize pathologic fractures related to cancer. Specific bone reconstruction algorithms and three-dimensional reconstructions further improve CT’s ability to detect rib pathology.

While CT appears to be the best imaging test for evaluating for rib fractures and associated injuries, it is relatively costly, is time-consuming, is not always available, and exposes the patient to a significant amount of radiation.

Also, while CT plays a vital role in major and penetrating trauma of the chest or abdomen, its use in other situations is more limited. Again, the issue of clinical impact of a diagnosis of rib fracture comes into play, and in this setting CT competes with plain radiography and ultrasonography, which are less costly and involve less or no radiation exposure.

Ultrasonography has advantages but is not widely used

Ultrasonography can be used to look for broken ribs and costal cartilage fractures. Associated injuries such as pneumothorax, hemothorax, and abdominal organ injury can also be evaluated. Studies have found it to be much more sensitive than plain radiography in detecting rib fractures,3,15 whereas other studies have suggested it is only equally sensitive or slightly better.7 It also has the advantage of not using radiation.

Because of a number of disadvantages, ultrasonography is rarely used in the evaluation of rib fracture. It is time-consuming and more costly than plain radiography. It is often not readily available. It can be painful, making it impractical for trauma patients. Its results depend greatly on the skill of the technician, and it is unable to adequately assess certain portions of the thorax (eg, the first rib under the clavicle, and the upper ribs under the scapula).7,15 Although able to detect some associated injuries, ultrasonography is not as sensitive and comprehensive as plain radiography and CT. Its role is therefore limited to situations in which the diagnosis of a rib fracture alone, in an accessible rib, is important.

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT