Introduction
Cervical spine x-ray interpretation is a vital skill in emergency medicine. This is particularly important as cervical spine injuries can leave patients with permanent neurological damage or death. While CT scans have overtaken X-rays as the primary form of cervical spine imaging, X-rays can be handy in rural areas or areas with limited resources. If in doubt, always ask for an expert opinion.
Cervical spine injuries commonly arise from motor vehicle accidents or falls from heights. They more commonly occur in men, and worse outcomes often happen to patients with underlying degenerative changes. Mechanisms of injuries causing fractures include flexion, extension, rotational, or vertical compression—these will be elaborated on further in this chapter. Cervical spine x-rays are somewhat useful if the patient is awake, stable, and has isolated injuries. In addition, they can be ordered in patients with upper airway obstruction symptoms, to look for soft tissue infections, foreign body demonstration, or if there is neck pain with no significant trauma.
Remember, cervical spine x-rays require manipulation of the neck to get clear views. Consider an alternative diagnostic choice like CT (Computed Tomography) or MRI (Magnetic Resonance Imaging) if cervical spine movement is restricted by a cervical collar. X-rays are also not advisable when neurological symptoms are present following trauma, in an uncooperative patient, or when a more accurate radiological modality is easily available.
Plain radiographs that display the lateral projection of the cervical spine, along with an open mouth view, are quite effective at identifying cervical spine fractures. Statistics indicate that the risk of overlooking a significant fracture is less than 1%. Including the anteroposterior (AP) projection raises the sensitivity to almost 100%. All three essential projections mentioned above can be seen in the figure below.
Before analyzing cervical radiographs, some additional facts need to be presented. Most spinal injuries occur at the junctions of the spine: craniocervical, cervicothoracic, thoracolumbar, and lumbosacral.
The only c-spine radiograph one should be satisfied with is the one showing all seven cervical vertebrae (C1–Th1). The C7–Th1 vertebrae may be obscured in muscular or obese patients, or in patients with spinal cord lesions that affect the muscles that normally depress the shoulders. Such lesions, which leave the trapezius muscle unopposed, occur in the lower cervical region. Shoulders can be depressed by pulling the arms down slowly and steadily or, if the patient is capable, by asking them to depress one shoulder and lift the other hand above their head to achieve the swimmer’s position, which better visualizes the lower vertebrae.
We will now present a systematic method for interpreting cervical spine x-rays. First, identification—make sure details are correctly matched to the patient by name, date of birth, record number, and the time the scan was done. Use an old x-ray of the patient as a comparison if the study has been done previously.
Interpretation
We utilize the ABCD system to comprehensively interpret cervical spine X-rays.
A: Alignment and adequacy
B: Bones
C: Cartilages
D: Dense soft tissue
Cervical spine X-rays typically include three views: the lateral view (or cross-table view), the odontoid view (or open mouth view), and the anterolateral view. If the lateral view is inadequate, an additional view called the “Swimmer’s view” may be requested to visualize the C7 and T1 vertebrae.
Lateral View
A: Adequacy and Alignment
An adequate image includes the base of the skull to the upper border of T1.
There are four parallel lines to note, from front to back (See image on the left, Courtesy of Dr Hussain Aby Ali). The front line (in purple), referred to as the anterior longitudinal line, runs along the anterior border of the vertebrae.
The second line, or the middle line, referred to as the posterior longitudinal line (in yellow), runs along the posterior border of the vertebrae.
Next, the spinolaminar line (in green) runs between the spinous process and lamina, along the anterior edge of the spinous process.
Lastly, the posterior spinous line (in blue) runs smoothly along the tips of the spinous processes.
The spinal cord lies between the posterior spinous and spinolaminar lines. Disruption of any of these lines indicates a fracture [1].
An important exception to the usual guidelines involves pseudo-subluxation of C2 and C3 in the pediatric population, which can lead to confusion. In these cases, it is essential to examine the spino-laminar line from C1 to C3. Be cautious of injury if the base of the C2 spinous process is more than 2 mm away from this line. Additionally, correlate your findings with any relevant soft tissue observations (see below under “D”).
On the lateral view, also assess the predental space, which is the distance between the anterior surface of the odontoid process and the posterior aspect of the anterior ring of C1. This distance should not exceed 3 mm in adults or 5 mm in children (see image below).
B: Bones
Examine the vertebrae for a normal bony outline and bone density. It is important to note any subtle changes in bone density, as these may indicate a compression fracture. Areas with decreased bone density are more vulnerable to fractures and are often seen in patients with conditions such as rheumatoid arthritis, osteoporosis, or metastatic osteolytic lesions. Acute compression fractures, in contrast, typically present as areas of increased bone density.
To check the integrity of the vertebrae, we must trace each vertebra individually. If there are any irregularities in the cortex of the bone, there may be a fracture.
As you trace the vertebrae on the right side (the image above), you may note that the sixth vertebra has slipped forward and is not continuous, which is an example of a vertebral fracture.
This is followed by scanning vertebrae C3–C7 in the usual manner, with no specific shadows or rings. The rest of the vertebral spaces must be equal, with a rectangular shape. Follow the spinous processes to look for any fractures [1].
Other examples are given below. See the fracture on 7th vertebral body (image A below), and fracture on spinous process of the 7th vertebrae (image B below).
Let us zoom in into the same image and focus on C1 and C2.
Start your day with a coffee—or rather, a coffee bean shadow—when interpreting c-spines. This shadow corresponds to the anterior arch of the atlas found in C1. Bear in mind that the peg might get in your way. With that, make sure the coffee bean shadow is adjacent to the odontoid peg. If not, think of a fracture!
When looking at C2, trace the ring, referred to as Harris’ ring (black color in the image above), which is the lateral mass of the vertebra. Discontinuity of the ring demonstrates a fracture.
C: Cartilage space assessment
n the assessment, examine the disc spaces, facet joint spaces, and interspinous spaces for any misalignments or increased space. Subluxations or facet dislocations can be identified by disruptions in the demarcated boxes, while any interspinous height exceeding 50% of the vertebral body indicates ligament disruption. On a good-quality lateral view x-ray of a healthy person, uniform intervertebral spaces should be evident.
An emergency physician may diagnose subluxations and dislocations of the facet joints by assessing the cartilage space between the vertebral corpora, facet joints, and spinous processes. However, increased interspinous distance by more than 50% suggests a ligamentous injury, and protective muscle spasms may complicate interpretation.
D: Dense soft tissue
Subsequently, we check the prevertebral space (in yellow), with the trachea sitting right in front of it (in red) (see the image below, courtesy of Hussain Aby Ali). Take C4 as your reference point (in purple). As a rule of thumb, the prevertebral space at or above C4 should be less than one-third the width of the vertebral body, while below C4 it should measure less than the width of the adjacent vertebra. In pediatrics, the prevertebral space at C4 is 7 mm, and at C6 it measures 14 mm or less, depending on age. In adults, the prevertebral space at C6 measures 22 mm. Enlarged measurements may indicate a hematoma related to a fracture, although normal measurements do not rule out a fracture [1].
The prevertebral soft tissues can serve as an indicator of acute swelling or hemorrhage resulting from an injury, and in some cases, may be the only indicator of an acute injury visible on an x-ray. The normal width of the prevertebral tissue decreases from C1 to C4 and increases from C4 downward. Normal measurements are less than 7 mm from C1 to C4 (less than half the vertebral body width at this level) and less than 22 mm below C5 (less than the vertebral body width at this level, as shown in Figure 9). The presence of air within the soft tissue could suggest a rupture of the esophagus or trachea.
Odontoid – Open Mouth View
A: Adequacy and Alignment
The odontoid x-ray is typically the second standard view obtained in the emergency department. Its primary goal is to visualize the odontoid process of the C2 vertebra and the C1 vertebra. This view can be taken with the patient’s mouth either open or closed.
When examining the odontoid x-ray, two key aspects are assessed: first, the distance between the odontoid process and the lateral masses of the C1 vertebra should be equal. If there is an inequality, it may indicate a slight rotation of the head. Second, considering the previous point, the margins of the C1 and C2 vertebrae should remain aligned.
B: Bones
The odontoid view is most helpful for assessing peg fractures and examining the lateral masses and spaces at C1 and C2. Start by drawing a line from the end of the lateral mass (in purple), along the shaft, up around the odontoid peg, and down to the other lateral end (in green), which marks C2. Next, demarcate C1’s lateral masses on each side and look for any irregularities or fractures.
C: Cartilage space assessment
The space between the peg and C1’s lateral masses must be equal (green asterisks), as should the spaces between C1 and C2 lateral masses (blue asterisks). Unequal lateral mass spaces could raise suspicion of subluxation, which may indicate that the transverse ligament holding the peg in place is torn. Alternatively, consider a Jefferson fracture, which will be discussed later in this chapter.
Draw an imaginary line along the lateral edges of C1 and C2, and check for any misalignment or displacement (red circles). It is important to note that when a patient’s cervical spine is rotated, the images may be inaccurate due to artifacts, which could be misconstrued as fractures, as shown in the image below [1].
An inappropriate imaging angle can result in an inconclusive image. In such cases, you may notice unequal spaces between the odontoid and C1 lateral masses, even when no underlying fractures are present. This situation should prompt a discussion with the radiologist or the consideration of further imaging, such as a CT scan or MRI.
Beware of the Mach effect!
The Mach effect is an optical illusion that can occur during imaging interpretation. It creates the appearance of a lower density at specific levels of the odontoid peg, which may falsely mimic an odontoid fracture. This illusion arises from the way edges and contrasts in the image are perceived by the human eye, often giving the impression of a discontinuity or fracture when none is present. It is crucial to recognize this phenomenon to avoid misdiagnosis, especially when interpreting odontoid fractures on radiographs. Careful examination and, if needed, correlation with additional imaging modalities such as CT or MRI can help confirm the true nature of the findings.
Anteroposterior View
A: Adequacy and Alignment
Images taken in this projection are usually less clear than the two mentioned above. The tips of the spinous processes should lie in a straight line along the midline, and the distances between the spinous processes should also be checked. Anomalies, such as bifid spinous processes, can complicate interpretation. The laryngeal and tracheal shadows should align down the middle, and the alignment of the lateral masses of the vertebrae should also be assessed.
An adequate image includes the vertebral bodies of the cervical vertebrae along with the superior border of the thoracic vertebrae. Vertical lines running across and along the spinous processes and vertebral bodies help assess alignment. Three lines are particularly important: the spinous process line (in blue), which runs through the spinous processes of C1 to C7, ensuring vertical alignment, and two lateral lines (in green), which run smoothly along the transverse processes, confirming their normal alignment.
B: Bones
The anteroposterior (AP) view of the cervical spine is one of the standard projections used during imaging. It is taken with the x-ray beam directed from the front (anterior) to the back (posterior) of the neck. While it provides a general overview of the alignment of the vertebrae and highlights features such as the spinous processes and transverse processes, this view may not always clearly demonstrate fractures.
Fractures, especially those involving the odontoid peg, vertebral bodies, or certain types of subtle cortical disruptions, can be challenging to detect due to the overlapping structures in this projection. Additionally, anomalies such as misalignment or crowding of the spinous processes might not be easily discernible. As a result, this view is often supplemented with lateral or oblique views and, in cases of doubt, with advanced imaging techniques like CT or MRI for a more definitive diagnosis.
The AP view remains an important tool for assessing gross abnormalities, vertebral alignment, and pathological conditions, such as tumors or significant bone density changes. However, its limitations in detecting subtle fractures underscore the need for careful correlation with clinical findings and additional imaging.
C: Cartilage space assessment
In an AP cervical spine x-ray, the assessment of cartilage spaces is crucial for evaluating alignment and potential injuries. A key rule to follow is the 50% rule: any increase in the cartilage space by more than 50% compared to adjacent spaces suggests anterior cervical dislocation. This finding is often associated with trauma, such as ligamentous injury or vertebral subluxation, but it is important to note that the 50% rule does not apply in cases of muscle spasm, particularly when the neck is in a flexed position.
To confirm the diagnosis and exclude vertebral slippage, it is essential to examine the lateral view. The lateral view provides additional details regarding the vertebral alignment, anterior displacement, and associated injuries that may not be visible on the AP view. Ensuring that the vertebrae are properly aligned without slippage is vital for accurate assessment and diagnosis.
By correlating findings from both the AP and lateral views, a clearer picture of cervical spine integrity can be obtained, helping to differentiate between conditions caused by trauma and those related to positional factors or muscle spasms.
D: Dense soft tissue
In the AP cervical spine view, it is important to assess for the presence of surgical emphysema or pneumothorax, as these findings can indicate significant underlying trauma.
Surgical Emphysema: Look for evidence of air trapped in the soft tissues of the neck. This appears as dark, radiolucent (black) streaks in areas where soft tissues should normally appear opaque. Surgical emphysema in the cervical region can result from tracheal or esophageal injury, penetrating trauma, or fractures that disrupt the airways. Its presence warrants immediate attention and further investigation to locate the source of the air leakage.
Pneumothorax: Although primarily evaluated using a chest x-ray, a pneumothorax might be visible on an AP c-spine x-ray, especially if significant. This is seen as an absence of lung markings on the affected side, with a radiolucent (black) space outlining the lung. Pneumothorax may occur in association with rib fractures or blunt trauma extending to the thoracic region and can contribute to respiratory distress.
Other Views
Swimmer’s view
When C7 or T1 is not clearly visible on the lateral view due to dense body musculature, obtaining a “Swimmer’s view” can be helpful. This imaging technique specifically focuses on the alignment of C7 and T1 at the cervico-thoracic junction. To achieve this view, patients are instructed to lower the shoulder on the same side as the area being examined [5].
Flexion and Extension Views
Oblique and flexion/extension views are not recommended in the emergency department setting as they can lead to further neurological injuries caused by manipulation. These views are only useful when interpreted by an experienced physician. Flexion and extension views are often contraindicated due to suspected unstable trauma or are impossible to perform because of spastic musculature following the injury (see Figure below). Additionally, unsupervised or forced flexion or extension in a patient with ligamentous injury can result in significant neurological damage. Therefore, other imaging modalities are necessary when a suspected injury is present.
Abnormal findings on cervical spine x-rays
C1 (Jefferson) fracture
A C1 fracture, also known as a Jefferson fracture, is best visualized on the odontoid view. This type of fracture typically results from axial loading, such as a heavy blow to the top of the head. The force compresses the cervical spine, leading to fractures in both the anterior and posterior arches of C1. These fractures are considered unstable because the transverse ligament, which stabilizes the relationship between the odontoid peg (dens) and the lateral masses of C1, is often disrupted.
Key imaging findings include widened spaces between the odontoid peg and the lateral masses of C1 (marked by orange asterisks). Additionally, the lateral masses of C1 may appear misaligned with those of C2 (marked by green circles), indicating instability [6]. The widening of these spaces and misalignment reflects the ligamentous injury and mechanical instability associated with this fracture.
Due to its unstable nature, a Jefferson fracture requires prompt recognition and further imaging, such as CT scans, to confirm the diagnosis and assess the extent of injury. Management often involves immobilization or surgical intervention, depending on the severity of the ligament disruption and alignment abnormalities.
C2 fractures
Odontoid peg fracture
To identify a C2 fracture, it is essential to evaluate both the open mouth (odontoid) view and the lateral view, as these complementary perspectives provide critical information about the integrity of the C2 vertebra.
Open Mouth (Odontoid) View:
This view is particularly useful for assessing the odontoid peg, also known as the dens. A discontinuity of the peg process, as shown in the image above, is a hallmark feature of a C2 fracture. This disruption indicates a break in the odontoid peg, which is often caused by significant trauma. The open mouth view allows for a clear examination of the alignment and spacing between the odontoid peg and the lateral masses of C1, helping to confirm the fracture.Lateral View:
The lateral view provides additional details about the alignment and integrity of the C2 vertebra. In cases of a C2 fracture:- Alignment Disruption: The normal alignment of the vertebral bodies is disturbed, indicating instability.
- Harris Ring Discontinuity: The Harris ring, a radiographic marker of the lateral mass of C2, appears interrupted, further confirming the presence of a fracture.
- Posterior Displacement of the Odontoid Peg: The odontoid peg may be displaced posteriorly, which can compromise the spinal canal and potentially compress the spinal cord.
Types of Odontoid Fractures
The graphical presentation above illustrates the three types of odontoid fractures, as labeled below:
Type I:
- Location: Fracture at the tip of the dens.
- Associated Injury: Alar ligament avulsion.
- Stability: This is considered a stable fracture.
Type II:
- Location: Fracture at the base of the odontoid process.
- Stability: This is an unstable fracture. It is the most common type of odontoid fracture and is associated with a high risk of nonunion due to poor blood supply at the fracture site.
Type III:
- Location: A fracture extending through the body of the axis (C2), curving laterally from one end to the other.
- Stability: This is also considered an unstable fracture. These fractures may disrupt the lateral masses of C2, further compromising spinal stability.
Recommended Management
- CT Scan: If any of these fractures are suspected or identified on plain x-rays, a CT scan is recommended for further evaluation to define the fracture line and assess the extent of bony disruption.
- Immobilization: The cervical spine should be immobilized using a cervical collar (c-collar) to prevent further injury.
- Consultation: Immediate consultation with neurosurgery is advised, as surgical intervention may be required, especially for unstable fractures (Type II and III).
These fractures, particularly Type II and III, have significant clinical implications due to their instability and proximity to critical neural structures, necessitating prompt diagnosis and intervention.
Hangman's fracture
A Hangman’s fracture is a bilateral fracture of the pars interarticularis of the C2 vertebra, often resulting in cervical spine instability. This type of fracture is best visualized on a lateral view, which reveals key findings:
Loss of Smooth Anterior Alignment
- The normal, smooth anterior alignment of the cervical spine is disrupted and replaced by a visible step, indicating displacement.
Cortical Discontinuity
- The fracture causes a break in the cortical bone, further demonstrating structural instability of the vertebra.
Mechanism of Injury
- Hyperextension Trauma
- This fracture is commonly caused by hyperextension injuries, such as those sustained in motor vehicle accidents.
- It is also seen in diving accidents, where a diver’s head strikes the pool floor upon impact.
Clinical Significance
- Hangman’s fracture is classified as unstable, as it compromises the integrity of the C2 vertebra and its supporting structures, potentially endangering the spinal cord.
Management
- Immediate immobilization of the cervical spine with a cervical collar is essential. Advanced imaging (CT or MRI) is recommended to further evaluate the extent of the injury and rule out associated soft tissue or ligamentous damage.
- Consultation with a neurosurgeon is critical for determining the need for surgical stabilization.
Importance of Recognizing C2 Fractures
C2 fractures, such as odontoid fractures or hangman’s fractures, are critical injuries due to their proximity to the spinal cord and brainstem. Prompt recognition using the open mouth and lateral views is vital to avoid neurological complications. Advanced imaging techniques, such as CT or MRI, are often required for further evaluation and to guide management strategies, which may include immobilization or surgical intervention.
Extension Teardrop Fracture
An extension teardrop fracture is a specific type of cervical spine injury in which a portion of the antero-inferior corner of the vertebra is fractured, resembling a teardrop shape. This injury is most commonly observed at C3 and is highly significant due to its association with instability and potential neurological compromise.
Fracture Appearance
- The fracture is located at the antero-inferior corner of the vertebral body, creating a teardrop-shaped fragment.
Mechanism of Injury
- Caused by sudden hyperextension of the neck, which disrupts the anterior longitudinal ligament.
- Often occurs in activities like diving, particularly when the diver strikes their head against a hard surface such as the pool floor.
Associated Injuries
- This type of fracture is frequently associated with central cord syndrome, a neurological injury caused by compression of the spinal cord, leading to weakness more pronounced in the upper limbs than the lower limbs.
Management
- Immediate Stabilization
- Apply a cervical collar (C-collar) to immobilize the spine and prevent further injury.
- Imaging
- A CT scan is the imaging modality of choice to confirm the diagnosis, evaluate the extent of the fracture, and assess for additional injuries or spinal canal compromise.
- Consultation
- Immediate consultation with a neurosurgeon is essential for determining the best treatment approach. Depending on the severity, surgical intervention may be necessary.
Flexion Teardrop Fracture
A flexion teardrop fracture is a severe and unstable cervical spine injury resulting from high-energy flexion trauma, frequently occurring at the C5/C6 level. This type of fracture is significant due to its association with spinal instability and neurological damage.
Radiographic Findings (Lateral View):
- The three longitudinal lines (anterior, posterior, and spinolaminar lines) are disrupted, indicating misalignment and instability.
- A teardrop-shaped fragment is seen at the antero-inferior corner of the vertebral body, representing the avulsed piece of bone.
Mechanism of Injury
- Caused by hyperflexion of the neck, which exerts excessive force on the cervical spine.
- This leads to a disruption of the posterior longitudinal ligament, further contributing to instability.
Neurological Association
- The injury often results in anterior cervical cord syndrome, characterized by loss of motor function and pain/temperature sensation below the level of injury, with preserved proprioception and vibration senses.
Management
- Immediate Stabilization
- Apply a cervical collar (C-collar) to immobilize the cervical spine and prevent further injury.
- Advanced Imaging
- A CT scan is the preferred imaging modality to confirm the diagnosis, evaluate the extent of the fracture, and identify associated injuries such as spinal canal compromise or ligamentous disruption.
- MRI may be indicated to assess soft tissue and spinal cord involvement.
- Consultation
- Urgent consultation with a neurosurgeon is essential due to the unstable nature of this fracture. Surgical stabilization is often required to restore spinal alignment and prevent further neurological deterioration.
Clinical Importance
The flexion teardrop fracture is considered one of the most unstable cervical spine injuries. Prompt recognition, immobilization, and appropriate surgical management are critical to improving patient outcomes and minimizing long-term neurological deficits.
Clay Shoveler's Fracture
A Clay Shoveler’s fracture is a stable fracture that involves an avulsion of the spinous process, typically occurring in the lower cervical or upper thoracic spine (most commonly at C6, C7, or T1).
Clinical Presentation
- Patients present with localized pain and tenderness over the affected area.
- The pain is often exacerbated by movement or palpation of the spine.
Stability
- This is considered a stable fracture as it does not involve the vertebral body, spinal canal, or neurological structures. However, the injury can still cause significant discomfort and impair mobility.
Examination and Management
- Neurological Assessment
- A neurological examination should always be performed to rule out any associated injuries or deficits, even though this fracture typically does not affect the spinal cord or nerves.
- Immobilization
- The patient should be placed in a cervical collar (c-collar) to immobilize the spine and alleviate pain during the acute phase of the injury.
- Imaging
- A lateral cervical x-ray is often sufficient to diagnose the fracture, but a CT scan can provide additional details if needed.
- Treatment
- Since this is a stable fracture, management is typically conservative, including pain control, immobilization, and physical therapy as needed.
Clay Shoveler’s fractures are generally associated with good outcomes, and patients can recover fully with appropriate care and immobilization.
Retropharyngeal abscess
Patients with a retropharyngeal abscess often present with:
- Sore throat and fever.
- Torticollis: The head is tilted to one side due to neck stiffness and discomfort.
- Dysphagia: Difficulty swallowing.
- Respiratory Distress: Severe cases may manifest with stridor, drooling, or increased breathing effort with retractions, indicating a compromised airway.
Management
- Immediate Interventions
- Patients in respiratory distress should be closely monitored as the airway may become obstructed, necessitating emergency airway management, including the potential need for a surgical airway (e.g., tracheostomy).
- Specialist Consultation
- A prompt otolaryngology consult is warranted for evaluation, incision and drainage (I&D) of the abscess, and initiation of intravenous antibiotics.
Radiographic Assessment
- Measuring the Retropharyngeal Space
- The retropharyngeal space is evaluated using lateral cervical spine x-rays.
- Between C2 and C4, the vertebral bodies can be divided into thirds. The retropharyngeal space should not exceed one-third the width of the corresponding vertebral body.
- At C4 and below, the vertebral bodies should be divided in half, with the prevertebral space width being approximately equal to the anterior half of the vertebral body [8].
- Signs of Retropharyngeal Abscess
- Widening of the retropharyngeal space beyond normal parameters is highly suggestive of an abscess.
- Additional findings may include air-fluid levels, soft tissue swelling, or displacement of adjacent structures.
Epiglottitis
Epiglottitis is a rapidly progressive and potentially life-threatening disease that primarily affects the upper airway. Patients often present with:
- Fever and sore throat as initial symptoms.
- Drooling and difficulty swallowing (dysphagia).
- Inspiratory stridor, indicating partial airway obstruction.
These symptoms suggest an urgent need for airway evaluation and management.
Lateral Neck X-ray
- The hallmark finding is the “thumb sign”, which represents the swollen epiglottis.
- Swelling of the epiglottis and aryepiglottic folds is characteristic of this condition.
- The epiglottis appears enlarged and rounded, resembling the shape of a thumb.
Importance of Early Recognition
- Epiglottitis can rapidly progress to complete airway obstruction, particularly in children.
- It is critical to recognize these findings on a lateral neck x-ray and act promptly to secure the airway.
Management
Patients showing signs of airway obstruction require immediate attention, with priority given to securing the airway. In severe cases, this may involve intubation, preferably using fiberoptic intubation in a sitting position, or tracheostomy if necessary. This procedure should be performed collaboratively with ENT surgeons and anesthesia professionals in a controlled environment.
As a temporary measure, nebulized racemic epinephrine can be administered to reduce airway swelling, and broad-spectrum antibiotics should be started promptly to treat the underlying infection. Supportive care, such as humidified oxygen, may also be beneficial. Additionally, a nasopharyngoscopy should be performed to directly visualize the epiglottis and assess the extent of swelling.
Laryngotracheobronchitis (Croup)
Laryngotracheobronchitis, commonly referred to as croup, presents with characteristic symptoms including:
- Barking cough, often likened to a seal’s bark.
- Inspiratory stridor, indicating upper airway obstruction.
- Drooling or dysphagia, in some cases.
- Signs of increased work of breathing, such as retractions and nasal flaring.
These symptoms are typically caused by inflammation and narrowing of the subglottic airway, often following a viral infection.
Radiographic Findings
- An anteroposterior (AP) neck x-ray may reveal the steeple sign, which represents narrowing of the subglottic trachea [10].
- The steeple sign is considered pathognomonic for croup, though it is also occasionally observed in bacterial tracheitis.
- A neck x-ray is not required for diagnosing croup but may be helpful to confirm the diagnosis when the patient is stable and cooperative [11].
While croup is usually a clinical diagnosis, imaging may be considered in atypical presentations or to rule out other conditions like epiglottitis or retropharyngeal abscess. Prompt recognition of croup and appropriate management can prevent complications associated with airway obstruction.
Clinical Decision Rule
There are two widely used scoring systems for neck injuries, primarily for diagnostic purposes: the National Emergency X-Radiography Utilization Study (NEXUS) criteria and the Canadian C-spine rules (CCR). Both have high sensitivity (89% and 98%, respectively) but low specificity (39% and 16%, respectively) [12]. Neither tool is used for patients over 65 years of age.
The NEXUS criteria can be easily remembered using the mnemonic NSAID:
- N: Neurological deficit
- S: Spine tenderness, midline
- A: Altered mental state
- I: Intoxicated
- D: Distracting injury
A positive finding in any of these categories requires imaging.
The Canadian C-spine rule, on the other hand, categorizes patients into two groups based on severity: high risk and low risk. It uses a stepwise, question-based approach. Patients who are 65 years or older, those with a high-risk mechanism of injury, or those presenting with neurological symptoms always require imaging.
Refer to the diagram for a simplified explanation.
Specific Patient Groups
Pediatrics
Younger patients have anatomical differences compared to adults, including a larger head, incomplete ossification of the vertebrae, and firm attachment of the ligaments to the spine, which predispose them to injuries. Poor balance and a flexible spine further increase the risk of injury. As children reach the age of 8, their balance improves, and the injury rates decrease.
Nevertheless, pediatric patients can sustain spinal cord syndromes similar to those in adults, which may cause lifelong disabilities. Examples include central cord syndrome, anterior cord syndrome, posterior cord syndrome, Brown-Séquard syndrome, and spinal shock. The decision to perform imaging and the modality chosen are based on criteria similar to those used for adults.
In pediatric trauma patients, the ABCDE trauma evaluation must be followed, as with adults. An important entity to consider is SCIWoRA (Spinal Cord Injury Without Radiographic Abnormality), which is defined specifically for children under 8 years of age. This condition occurs when hyperextension forces injure the neck, leading to neurological deficits without abnormalities detected on x-rays or CT scans. MRI is required to assess the severity and prognosis. Favorable MRI findings include small hematomas and edema, whereas large hematomas or spinal cord transections are considered unfavorable [13].
Geriatrics
Motor vehicle accidents and falls from standing or sitting positions remain the two most common causes of cervical spine injuries in geriatric patients [14]. Due to anatomical degenerative changes and low bone density, even low-energy mechanisms can result in high-impact injuries. CT scanning is recommended for evaluating suspected cervical spine injuries in geriatric patients, who should always be considered trauma patients.
Pregnant Patients
Pregnant individuals involved in trauma require standard trauma protocols for evaluation and treatment, including CT imaging. Although CT imaging exposes both the mother and fetus to radiation, this exposure is not associated with an increased risk of fetal anomalies. However, the use of CT imaging should be carefully considered, with discussions involving the patient or their family, the radiologist, and a senior physician [15].
Authors
Maitha Mohammed Alneyadi
Emergency Medicine Department, Tawam Hospital, Al Ain, United Arab Emirates
Mansoor Masarrat Husain
Emergency Medicine Department, Tawam Hospital, Al Ain, United Arab Emirates
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FOAM and Further Reading
Reviewed and Edited By
Arif Alper Cevik, MD, FEMAT, FIFEM
Prof Cevik is an Emergency Medicine academician at United Arab Emirates University, interested in international emergency medicine, emergency medicine education, medical education, point of care ultrasound and trauma. He is the founder and director of the International Emergency Medicine Education Project – iem-student.org, chair of the International Federation for Emergency Medicine (IFEM) core curriculum and education committee and board member of the Asian Society for Emergency Medicine and Emirati Board of Emergency Medicine.
