Cervical spine trauma

DR ALI JIWANIJNMC WARDHA

anatomy

• atlas

• Axis

• C4 of typical cervical vertebra (c3 – c7)

Various views of cervical spine

• THE LATERAL VIEW:• The lateral view is the most important in the routine

trauma series.• It is essential that all seven cervical and the first

thoracic vertebrae be clearly displayed• Pulling downward on the arms is frequently advocated.• Swimmers view can be taken if no shoulder injury• Lateral tomogram can be taken in cases of

unsatisfactory conventional radiography

Vertebral lines

Three column -- denis

C2- 7mm or lessC6- 22mm or less 14mm or less

ANTEROPOSTERIOR VIEW

• The information available on the AP view is important, especially in assessing soft tissue injuries which may produce only subtle changes on the lateral view.

• The AP view may also provide valuable clues in evaluating the cervicothoracic region

OBLIQUE VIEW

• The oblique view can be obtained by angling the tube on conventional equipment or rotating the arm on a C-arm tomographic trauma unit.

• This view is important for evaluating the posterior structures and especially for detecting subtle perching or locking of the facets

OPEN MOUTH ODONTOID VIEW

• This view is useful in evaluating the odontoid and the relationships of CI-C2

• In some patients, it is difficult to visualize the entire odontoid. Angling the tube as would be done for an AP Waters view

PILLAR VIEWS

• The patient’s head must be rotated to obtain pillar views.

• Proper alignment of each set of pillars is not always possible using a single tube angle (usually the tube is angled 20-30 degree. The pillar view is useful in evaluating the articular pillars and lamina .

MOTION (FLEXION, EXTENSION) VIEWS

• Fluoroscopically positioned flexion and extension views are important in assessing soft tissue injury and potential instability

• this study should be reserved for those patients without fracture.

• Post traumatic muscular spasm and underlying bony injury is great challenge for this study

CT

• CT scan is not mandatory for every patient with cervical spine injury. Most injuries can be diagnosed by plain films. However, if there is a question on the radiograph, CT of the cervical spine should be obtained.

• CT scan are particularly useful in fractures that result in neurologic deficit and in fractures of the posterior elements of the cervical canal (e.g. Jefferson's fracture) because the axial display eliminates the superimposition of bony structures.

• The advantages of CT are:• 1. CT is excellent for characterizing fractures and

identifying osseous compromise of the vertebral canal because of the absence of superimposition from the transverse view. The higher contrast resolution of CT also provides improved visualization of subtle fractures.

• 2. CT provides patient comfort by being able to reconstruct images in the axial, sagittal, coronal, and oblique planes from one patient positioning.

• The limitations of CT are: • 1. difficult to identify those fractures oriented

in axial plane (e.g. dens fractures). • 2. unable to show ligamentous injuries. • 3. relatively high costs.

MRI

• MRI is indicated in cervical fractures that have spinal canal involvement, clinical neurologic deficits or ligamentous injuries. MRI provides the best visualization of the soft tissues, including ligaments, intervertebral disks, spinal cord, and epidural hematomas.

• The advantages of MRI are: • 1. excellent soft tissue constrast, making it the study of

choice for spinal cord survey, hematoma, and ligamentous injuries.

• 2. provides good general overview because of its ability to show information in different planes (e.g. sagital, coronal, etc.).

• 3. ability to demostrate vertebral arteries, which is useful in evaluating fractures involving the course of the vertebral arteries.

• 4. no ionizing radiation.

• The disadvantages of MRI are: • 1. loss of bony details. • 2. relatively high cost.

Mechanism of injury

Hyper extension

Cervical spine fracturesFractures of the Atlas

• Jefferson’s Fracture (Bursting Fracture of the Atlas):

• A bursting fracture of the ring of the atlas, with fractures through the anterior and posterior arches,

• Jefferson’s fracture is a compression injury created by a forceful blow on the skull vertex, which is transmitted through the occipital condyles to the lateral masses of the atlas.

• The force displaces the lateral masses laterally, classically producing the fractures on each side of the anterior and posterior arches of the atlas. CT has since demonstrated variations in this fracture pattern

• Death or significant neurological deficit is uncommon, though approximately 50% of cases will have persistent neck pain, stiffness, and occipital dysesthesia

• Radiographic features: the key radiographic view is the AP open mouth, which shows displacement of the lateral masses of vertebrae C1 beyond the margins of the body of vertebra C2. A lateral displacement of >2 mm or unilateral displacement may be indicative of a C1 fracture. CT is required to define the extent of fracture and to detect fragments in the spinal canal.

• Simulation of a Jefferson’s fracture (pseudo-spread) may occur in four circumstances. In children < 10 years of age,

• most commonly around 4 years, the atlas may grow at a greater rate than the axis.

• Developmental anomalies of the atlas, such as localized lateral mass malformation or combined anteroposterior (AP) spina bifida of the atlas, can produce a similar appearance. Rotary atlantoaxial subluxation and torticollis may also mimic a Jefferson’s fracture. Such variations usually do not produce lateral offset of > 2 mm, whereas a Jefferson’s fracture typically exceeds 3 mm.

Posterior Arch Fracture of the Atlas.

• The most common fracture of the atlas is the posterior arch fracture, accounting for at least 50% of all atlas fractures

• The fracture is usually a bilateral vertical fracture through the neural arch,

• This fracture occurs as a result of the posterior arch of the atlas being compressed between the occiput and the large posterior arch of the axis during severe hyperextension..

• best seen on the lateral projection• Serious complications are unusual, though

associated cervical fractures may precipitate spinal cord injury.

• Close anatomic proximity of the vertebral artery to the fracture site may occasionally lead to serious vascular injury.

Rupture of the Transverse Ligament

• Isolated traumatic disruption of the transverse ligament is infrequent

• Rupture of the ligament is common in association with Jefferson’s fracture, inflammatory arthritis (e.g., rheumatoid arthritis, psoriasis, ankylosing spondylitis, and Reiter’s syndrome)

• A key radiologic feature of a ruptured transverse ligament is an abnormally wide atlantodental interspace (ADI) (> 3 mm in adults and 5 mm in children), most pronounced in flexion

• The posterior cervical line will also be disrupted Cord compression may not be clinically apparent until considerable anterior displacement of the atlas (up to 10 mm) has occurred

Fractures of the Axis

• Hangman’s Fracture (Traumatic Spondylolisthesis).

• Fractures of the neural arch of the axis are among the most common injuries of the cervical spine

• They are usually the results of automobile accidents in which there is abrupt deceleration from a high speed, though the fracture occurs during hyperextension

• The distribution of the fracture is similar to that resulting from judicial hanging

• The fracture occurs as a bilateral disruption through the pedicles of the axis.

• The fracture lines are best seen on CT or the lateral view just anterior to the inferior facet, usually in association with anterior displacement of C2 on C3.

• An avulsion of the anteroinferior corner of the vertebral body (teardrop fracture) often occurs simultaneously.

• Extension of the fracture into the transverse foramen may precipitate vertebral artery injury.

• Classification of Hangman' s fractures • Type I (65%) 1. hair-line fracture 2. C2-3 disc normal• Type II (28%)1. displaced C2 2. disrupted C2-3 disc 3. ligamentous rupture with instability 4. C3 anterosuperior compression fracture• Type III (7%)1. displaced C2 2. C2-3 Bilateral interfacet dislocation 3. Severe instability

Teardrop Fracture.

• The teardrop fracture is an avulsion of a triangular-shaped fragment from the anteroinferior corner of the axis body

• Although teardrop fractures can occur at any cervical body, the lesion is most common at the axis. At this level an acute hyperextension is the usual mechanism of injury, which explains its common occurrence in combination with a hangman’s fracture

Odontoid Process Fracture

• Fractures of the odontoid process are common traumatic injuries of the cervical spine

• Pathologic fracture may complicate metastatic carcinoma, multiple myeloma and other tumors, rheumatoid arthritis, and ankylosing spondylitis as well as other causes for osteopenia

• Type I.• Type I is an avulsion of the tip of the odontoid

process as a result of apical or alar ligament stress. It is an uncommon injury and is rarely complicated by non-union

• Type II. A fracture at the junction of the odontoid process and the body of the axis. This is the most common odontoid process fracture and the one that most frequently results in non-union owing to reduced vascularity of the separated fragment.

• During union, hypertrophic callus may induce myelopathy. Post-fracture osteolysis of the dens has been recorded.

• Patients with dislocation of > 5 mm should be evaluated for surgical intervention

• Type III:In type III fractures, the fracture is found deep within the vertebral body, below the base of attachment of the odontoid process to the body. This type is almost as common as type II, though it heals more readily

• The most reliable imaging findings consist of the fracture line, odontoid displacement, disrupted axis (Harris) ring, enlargement of C2 body, and retropharyngeal swelling

• Displacement of the odontoid in either the anterior or posterior position is usually < 3 mm

• This displacement creates an offset of the posterior cervical line (PCL) of the atlas as it relates to the normally positioned axis. Impingement on the spinal cord occurs in isolated rupture of the transverse ligament with an intact odontoid process, creating a guillotine, or pincers, effect on the cord. A lateral tilt of the odontoid process > 5° indicates an underlying fracture.

• Os odontoideum represents a developmental failure of the dens to unite with the body of the odontoid but exhibits distinctive radiographic features that allow differentiation from acute fracture

Os Odontoideum

• Wide Zone of separation• Round, smooth, sclerotic margins• Vertical Odontoid orientation• Interrupted Posterior cervical line• Increased Anterior tubercle size or density

Vertebral Body Compression Fractures

• Wedge Fracture:A wedge fracture occurs as a result of mechanical compression of the involved vertebra between the adjacent vertebral bodies from forced hyperflexion

• This is a stable fracture• The lateral radiograph is diagnostic• If the anterior height of a vertebral body measures

at least 3 mm less than the posterior height, a fracture of the vertebral body can be assumed.

Burst Fracture.

• A burst fracture is precipitated by vertical compression to the head propelling the nucleus pulposus through the endplate into the vertebral body.

• The force fractures the vertebra vertically, causing a comminution of the vertebral body with the fragments migrating centrifugally.

• The lateral radiograph reveals a comminuted vertebral body, which is usually flattened centrally

Clay Shoveler’s Fracture

• Clay shoveler’s fracture (coal-miner’s or root-puller’s fracture) is an avulsive injury of the spinous process

• It results from abrupt flexion of the head, such as is found in automobile accidents, diving, or wrestling injuries or from repeated stress caused by the pull of the trapezius and rhomboid muscles on the spinous process

• The spinous avulsion most commonly occurs at C7, with C6 and T1 also frequently involved.

Lamina and Transverse Process Fractures

• Laminar fractures occur in the middle to lower cervical spine, with C5 and C6 being the most common sites. While difficult to see on standard views, they are readily depicted on CT images

• Severe trauma with lateral flexion is necessary, and, as such, these often coexist with other cervical fractures and brachial plexus lesions

• The fracture line tends to localize near its junction with the pedicle and, if in continuity with the transverse foramen, may produce vertebral artery injury.

Lamina and Transverse Process Fractures

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