Official reprint from UpToDate® www.uptodate.com

©2013 UpToDate®

AuthorsAmy Kaji, MD, PhDRobert S Hockberger, MD, FACEP

Section EditorMaria E Moreira, MD

Deputy EditorJonathan Grayzel, MD, FAAEM

Spinal column injuries in adults: Definitions, mechanisms, and radiographs

Disclosures

All topics are updated as new evidence becomes available and our peer review process is complete.Literature review current through: Mar 2013. | This topic last updated: nov 29, 2012.

INTRODUCTION — This topic review describes injuries to the cervical, thoracic, and lumbosacral spinal column,

including fractures, dislocations, and subluxations of the vertebrae, and injuries to the spinal ligaments. The

importance of recognizing and managing injuries to the spinal column is underscored by their association with

spinal cord injury.

The management of spinal column injuries and other issues related to spinal cord injury are discussed elsewhere.

(See "Evaluation and acute management of cervical spinal column injuries in adults" and "Acute traumatic spinal

cord injury" and "Anatomy and localization of spinal cord disorders" and "Evaluation of cervical spine injuries in

children and adolescents" and "Overview of cervical spinal cord and cervical peripheral nerve injuries in the young

athlete".)

EPIDEMIOLOGY — Among patients included in a large trauma registry, approximately 3 percent of those with

blunt trauma sustain a spinal column injury, such as spinal fracture or dislocation, and 1 percent sustains a spinal

cord injury [1]. Spinal column injury rates reported in other studies range from 2 to 6 percent [2]. The incidence is

likely to be significantly higher in patients with head trauma and those who are unconscious at presentation.

Fracture of the thoracolumbar spine, including spinous and transverse process fractures, may occur in as many as

8 to 15 percent of blunt trauma patients cared for at major trauma centers [3].

A systematic review of 13 international studies found great variation (up to a threefold difference) in the rate of spinal

column injury among nations, particularly between developed and developing nations [4,5]. Most studies

demonstrate a bimodal age distribution where the first peak is found in young adults between 15 and 29 years of

age and a second peak in adults older than 65 years of age. Mortality is significantly higher in elder patients [6].

Spinal column injuries are more common in males.

Note that statistics from trauma registries can be incomplete and inaccurate, depending on the inclusion criteria,

and may underestimate the number of patients with spinal column injury. As examples, victims who die at the

accident scene and patients whose neurologic deficits rapidly improve are often not included.

Motor vehicle related accidents account for almost half of all spinal injuries [7], and speeding, alcohol intoxication,

and failure to use restraints are the major risk factors. Occupants involved in a rollover accident are at increased

risk of a cervical spine injury [8]. Other common causes include falls, followed by acts of violence (primarily gunshot

wounds), and sporting activities. The falls of older adults account for a growing proportion of spinal injuries,

reflecting the aging population of many developing countries. Missed or delayed diagnosis of spinal column trauma

results in a 7.5-fold increase in the incidence of neurologic injuries [7].

ANATOMY — The human spine consists of 33 bony vertebrae: 7 cervical, 12 thoracic, 5 lumbar, 5 sacral (fused),

and 4 coccygeal (usually fused) [9]. These 26 individual units are separated by intervertebral disks and connected

by a network of ligaments. The vertebral column provides the body's basic structural support and also protects the

spinal cord, which extends from the midbrain caudally to the level of the second lumbar vertebra and then continues

as the cauda equina.

Pictures and radiographs depicting the details of spinal anatomy are found below:

Spine anatomy overview (figure 1 and image 1)

Vertebral anatomy (figure 2)

Cervical vertebrae (figure 3)

C1 and C2 vertebrae details (figure 4)

Thoracic vertebrae (figure 5)

Cervical joints and ligaments (figure 6)

Skull and superior cervical spine interface (figure 7)

Due to its exposed location above the torso and its inherent flexibility, the cervical spine is the most commonly

injured part of the spinal column. Within the cervical spine, the most common sites of injury are around the second

cervical vertebra (C2, or axis) or in the region of C5, C6 and C7 [2].

In contrast, the thoracic spine is rigidly fixed, as the thoracic ribs articulate with the respective transverse

processes and sternum. Thus, a great amount of force is necessary to damage the thoracic spine of an otherwise

healthy adult. In older adults with osteoporosis or patients with bone disease or metastatic lesions minor trauma

may be sufficient to cause a compression fracture.

The second most commonly injured region is the thoracolumbar (TL) junction. The orientation of the facet joints at

the TL junction may concentrate forces created from traumatic impact at this level [10]. At the TL junction, the

spinal column changes from a kyphotic to a lordotic curve. Ninety percent of all TL spine injuries occur in the region

between T11 and L4. However, these injuries rarely result in complete cord lesions as the spinal canal is relatively

wide at this level [11].

MECHANISMS — Spinal column injury may result in spinal cord trauma through a number of mechanisms [12]:

Transection – Penetrating or massive blunt trauma resulting in spinal column injury may transect all or part

of the spinal cord; less severe trauma may have similar neurologic effects by displacing bony fragments into

the spinal canal or through disk herniation. (See "Acute traumatic spinal cord injury".)

Compression – When elderly patients with cervical osteoarthritis and spondylosis forcibly extend their neck,

the spinal cord may be compressed between an arthritically enlarged anterior vertebral ridge and a

posteriorly located hypertrophied ligamentum flavum. Injuries that produce blood within the spinal canal can

also compress the spinal cord. (See "Disorders affecting the spinal cord", section on 'Spinal epidural

hematoma'.)

Contusion – Contusions of the spinal cord can occur from bony dislocations, subluxations, or fracture

fragments.

Vascular injury – Primary vascular damage to the spinal cord should be suspected when there is a

discrepancy between a clinically apparent neurologic deficit and the known level of spinal column injury. As

an example, when a lower cervical dislocation compresses the vertebral arteries within the spinal foramina of

the vertebrae, thrombosis and decreased blood flow through the anterior spinal artery may result. The

anterior spinal artery originates from both vertebral arteries at the level of C1. This injury may erroneously

appear to localize to the level of C1 or C2 rather than the site of the dislocation. (See "Disorders affecting the

spinal cord", section on 'Spinal cord infarction'.)

Certain conditions predispose patients to cervical spinal column injury. Down syndrome patients are predisposed to

atlanto-occipital dislocation; patients with rheumatoid arthritis are prone to rupture of the transverse ligament of C2.

(See "Clinical features and diagnosis of Down syndrome" and "Cervical subluxation in rheumatoid arthritis".)

CERVICAL SPINAL COLUMN INJURY

Cervical spinal column injury classification — Acute cervical spinal column injury may be classified according

to the stability of the injury, its location, or the mechanism (flexion, flexion-rotation, extension, and vertical

compression) (table 1) [13,14].

To assess the stability of cervical spinal column injuries below C2, the spine is viewed as consisting of two

columns. The anterior column is formed by vertebral bodies and intervertebral disks, which are held in alignment by

the anterior and posterior longitudinal ligaments. The posterior column, which contains the spinal canal, is formed

by the pedicles, transverse processes, articulating facets, laminae, and spinous processes. The nuchal ligament

complex (supraspinous, interspinous, and infraspinous ligaments), capsular ligaments, and ligamentum flavum hold

the posterior column in alignment.

If both columns are disrupted, the cervical spine can move as two independent units, and there is a high risk of

causing or exacerbating a spinal cord injury [14]. In contrast, if only one column is disrupted and the other column

maintains structural integrity, the risk of spinal cord injury is far less.

Atlanto-occipital dislocation — Pure flexion injuries involving the atlas (C1) and the axis (C2) can cause an

unstable atlanto-occipital or atlanto-axial joint dislocation, with or without an associated odontoid fracture (image 2).

Several measurements are used to determine the presence of atlanto-occipital joint dislocation on plain lateral x-ray

of the cervical spine; however, their accuracy and interobserver reliability are not well studied in trauma patients

[15].

The basion-posterior axial line interval (BAI) and the basion-dental interval (BDI) demonstrate consistent

relationships in normal adults (figure 8) [16]. They are determined by using a line drawn along the posterior border of

the anterior body of C2. Two lines are then drawn from this line: one perpendicularly to the basion (ie, tip of the

clivus at the occipital base) and another from the basion to the tip of the dens. A sum of these two lines originating

from the basion exceeding 12 mm suggests atlanto-occipital joint dislocation.

The Powers ratio is commonly used to assess for atlanto-occipital dislocation (figure 9). It is defined by the ratio of

BC:OA, where BC is the distance between the basion and the midpoint of the posterior laminar line of C1, and OA

is the distance between the midpoint of the posterior margin of the foramen magnum (opisthion) and the midpoint of

the posterior surface of the anterior arch of C1 [17]. A ratio greater than one suggests anterior subluxation.

Another radiologic finding suggestive of an atlanto-occipital dislocation is disruption of the “basilar line of

Wackenheim,” a line drawn from the posterior surface of the clivus to the odontoid tip [18,19]. Normally, the inferior

extension of this line should just touch the posterior aspect of the tip of the odontoid. If the line runs anterior or

posterior to the odontoid tip, this suggests an atlanto-occipital dislocation.

Atlanto-axial dislocation — Rotary atlanto-axial dislocation is an unstable injury, caused by a flexion-rotation

mechanism, best visualized on open-mouth odontoid radiographs or CT scan (figure 10). The interpretation of

odontoid radiographs warrants careful attention, since there may be false positive asymmetry between the odontoid

process and the lateral masses of C1 if the skull is rotated (image 3). When the x-ray reveals symmetric basilar

skull structures, a unilaterally magnified lateral mass confirms a C1-C2 dislocation.

C1 (Atlas) fractures

Burst (Jefferson) — The Jefferson fracture of C1 is highly unstable and occurs when a vertical compression

force is transmitted through the occipital condyles to the lateral masses of the atlas (image 4 and image 5 and

figure 11). This force drives the lateral masses outward, resulting in fractures of the anterior and posterior arches of

the C1, with or without disruption of the transverse ligament. Disruption of the transverse ligament determines

instability.

Prevertebral hemorrhage combined with disruption of the transverse ligament may cause an increase in the

predental space between C1 and the odontoid (dens) seen on the lateral radiograph. A predental space greater than

3 mm in adults or 5 mm in children is abnormal [20]. In the AP projection (open-mouth or odontoid view), the

masses of C1 lie lateral to the outer margins of the articular pillars of C2 (image 6). The Jefferson fracture may be

difficult to recognize on plain x-ray if there is minimal displacement [21].

The transverse ligament is presumed to be disrupted if the interval between the atlas and the dens is increased on a

lateral radiograph, or the lateral masses of the atlas extend laterally beyond those of the axis on the odontoid

radiograph. In such instances, clinicians should obtain a CT scan of the cervical spine.

Posterior arch — A posterior neural arch fracture of C1 results from compression of the posterior elements

between the occiput and the spinous process of C2 during forced neck extension. A vertical fracture line through

the posterior neural arch is seen on lateral x-ray (image 7). Although mechanically stable because the anterior arch

and the transverse ligament remain intact, this fracture is potentially dangerous because of its location. Anterior

displacement of the atlas greater than 1 cm can injure adjacent spinal cord.

C2 (Axis) pedicle fractures — Traumatic spondylolysis of C2 (so-called "hangman's fracture") is an unstable

injury that occurs when the cervicocranium (the skull, atlas, and axis functioning as a unit) is thrown into extreme

hyperextension as a result of abrupt deceleration (ie, forced extension of an already extended neck) (image 8 and

figure 12). Bilateral pedicle fractures of the axis may occur with or without dislocation in this circumstance.

Although this lesion is unstable, spinal cord damage is often minimal because the AP diameter of the neural canal

is greatest at C2, and bilateral pedicle fractures permit spinal canal decompression [22].

Odontoid fractures — Forceful flexion or extension of the head in an anterior-posterior orientation (ie, sagittal

plane), as might occur with a forward fall onto the forehead, may result in a fracture of the odontoid process, also

called the dens. Fractures can occur above the transverse ligaments (type I) or, most commonly, at the base of the

odontoid process where it attaches to C2 (type II) (image 9 and figure 13). Type I fractures are stable. Although

spinal cord injury is uncommon, type II odontoid fractures are unstable and complicated by nonunion in over 50

percent of patients treated with halo vest immobilization [23]. Slight angulation of the force may result in extension

of the fracture through the upper portion of the body of C2 (type III) (image 10 and figure 13). Type III fractures are

mechanically unstable, since they allow the odontoid and the occiput to move as a unit. Odontoid fractures are best

seen on the AP odontoid radiograph (ie, open-mouth view) and cause prevertebral soft tissue swelling on lateral

radiographs. Caution is necessary when interpreting the open mouth view as a radiographic line created by the

space between the two front incisors may be confused for a dens fracture.

Anterior wedge — Forceful flexion of the cervical spine can compress the anterior portion of a vertebral body,

creating an anterior wedge fracture. Spinal instability can result if anterior wedge fractures are severe (loss of over

half the height of the anterior vertebral body) or multiple adjacent wedge fractures occur (image 11 and image 12

and figure 14).

In pure flexion injuries below C2, the strong nuchal ligament complex usually remains intact, and most of the force

is expended on the vertebral body anteriorly, causing a simple wedge fracture [22]. Radiographically, the height of

the anterior border of the vertebra is diminished, and prevertebral soft tissue swelling is present. Because the

posterior column remains intact, this injury is usually stable and rarely associated with spinal cord injuries.

Flexion teardrop — A flexion teardrop fracture results when severe flexion and compression cause one vertebral

body to collide with the body below, leading to anterior displacement of a wedge-shaped fragment (resembling a

teardrop) of the antero-inferior portion of the superior vertebra (image 13 and figure 15). They usually occur in the

lower cervical spine.

On plain lateral radiographs, the fractured vertebra appears to be divided into a smaller anterior fragment and a

larger posterior piece. The larger piece displaces posteriorly as a unit with the superior cervical spine relative to the

vertebrae below. The anterior fragment typically remains aligned with the inferior cervical vertebrae. If there is no

posterior displacement of the superior column, widening of the interlaminar and interspinous spaces supports the

diagnosis of a flexion teardrop fracture [24].

The severe anterior flexion involved in this injury creates distraction forces at the posterior cervical spine and

disruption of the posterior longitudinal ligament. Thus, flexion teardrop fractures are highly unstable. They are

associated with acute anterior cervical cord syndrome. (See "Anatomy and localization of spinal cord disorders",

section on 'Ventral (anterior) cord syndrome'.)

Extension teardrop — An extension teardrop fracture occurs when abrupt neck extension causes the anterior

longitudinal ligament to avulse the antero-inferior corner from the remainder of the vertebral body, producing a

triangular-shaped fragment (image 14 and figure 16). This unstable injury is found most often at C2, but can also

occur at C5 to C7 with diving accidents and can be associated with a central cord syndrome [12].

Although similar in radiographic appearance to the flexion teardrop fracture, the vertebra involved in an extension

teardrop injury generally does not lose height. In contrast, a vertebra with a flexion teardrop fracture may lose height

from compression [24]. (See "Anatomy and localization of spinal cord disorders", section on 'Central cord

syndromes'.)

Spinous process fractures — The clay shoveler's fracture, an isolated fracture of one of the spinous processes of

the lower cervical vertebrae, is a stable injury (image 15). It derives its name from its occurrence in clay miners

during the 1930s. Today, this fracture is more commonly seen following direct trauma to the spinous process and

after motor vehicle crashes involving sudden deceleration that result in forced neck flexion.

Burst fractures — Vertical compression injuries occur in the cervical and lumbar regions when axial loads are

exerted on the spine. Such forces are applied from above (via the skull) or below (via the pelvis or feet), and may

cause one or more vertebral body end-plates to fracture. When the nucleus pulposus of the intervertebral disk is

forced into the vertebral body, the body shatters outward, resulting in a burst fracture. The lateral radiograph shows

a comminuted vertebral body and loss of vertebral height, while the anterior-posterior (AP) radiograph demonstrates

a characteristic vertical fracture of the vertebral body (image 16).

Although technically burst fractures are “stable” since all ligaments remain intact, posteriorly displaced fracture

fragments may impinge on the spinal cord, causing an anterior cord syndrome. (See "Anatomy and localization of

spinal cord disorders", section on 'Ventral (anterior) cord syndrome'.)

To reflect this risk of spinal cord injury, burst fractures can be classified as unstable if any of the following are

present:

Associated neurologic deficits

Loss of greater than 50 percent of vertebral body height

Greater than 20 degrees of spinal angulation

Compromise of more than 50 percent of the spinal canal [18].

Laminar fractures — Most laminar fractures of the cervical spine are associated with other fractures, such as

burst fractures or fracture dislocations, which usually determine the stability of the injury (image 17) [25]. The

pattern of the fracture often reflects the mechanism of injury. Vertical lamina fractures are thought to result from

axial loading, whereas transverse fractures often represent avulsion fractures from hyperflexion. Although rare,

isolated lamina fractures, which are generally not associated with instability, can be treated nonoperatively with

cervical collar immobilization [26].

Facet dislocations

Bilateral — Bilateral facet dislocations occur when flexion forces extend anteriorly, causing disruption of the

annulus fibrosus of the intervertebral disc and the anterior longitudinal ligament, resulting in extreme instability. The

inferior articulating facets of the upper vertebra pass over the superior facets of the lower vertebra, resulting in

anterior displacement of the spine. Complete spinal cord injury most often results. Radiographically, the

displacement will appear to be greater than one half of the anteroposterior (AP) diameter of the lower vertebral body

with the superior facets anterior to the inferior facets, which is best seen on the lateral view (image 18 and image

19).

Unilateral — Unilateral facet dislocations involve flexion and rotation. Rotation occurs around one of the facet

joints; dislocation occurs at the contralateral facet joint, with the superior facet moving over the inferior facet, and

coming to rest within the intervertebral foramen (image 20).

On a lateral plain radiograph, the two lateral masses of the dislocated vertebrae may partially overlap giving the

appearance of a bow tie (radiologists may refer to a bowtie or double diamond sign) (image 21). Since the

dislocated articular mass is locked in place, this is a stable injury despite posterior ligament complex disruption.

Spinal cord injury rarely occurs following isolated unilateral facet dislocation. However, associated fractures of the

facet or surrounding structures can create instability [27].

Ligamentous injuries and SCIWORA — The definition of spinal cord injury without radiographic abnormality

(SCIWORA) varies among studies, but it is often defined as the presence of neurologic deficits in the absence of

bony injury on a complete, technically adequate, plain radiograph series or CT scan. This injury pattern is more

common in children and has been attributed to several causes, including ligamentous injuries, disc prolapse, and

cervical spondylosis. (See "Evaluation of cervical spine injuries in children and adolescents".)

Clinicians should suspect a cervical ligamentous injury in the injured patient who has persistent severe pain or

paresthesias or focal neurologic findings (eg, upper extremity weakness) in the absence of a fracture seen on plain

radiographs or CT. Such injuries may be unstable, although they are rarely associated with permanent neurologic

damage. Evaluation of suspected ligamentous injury or SCIWORA in adults is discussed separately. (See

"Evaluation and acute management of cervical spinal column injuries in adults", section on 'Evaluation for

ligamentous injury and SCIWORA'.)

THORACIC AND LUMBAR (TL) SPINAL COLUMN INJURY

TL spinal column injury classification — In contrast to the two column scheme for cervical spinal column injury,

a three column scheme may be used to describe injuries of the thoracic and lumbar (TL) spinal column [28]. The

three columns are anterior, middle, and posterior (figure 17). The anterior column includes the anterior longitudinal

ligament, the annulus fibrosus, and the anterior half of the vertebral body. The middle column comprises the

posterior longitudinal ligament, the posterior annulus fibrosus, and the posterior half of the vertebral body. The

posterior column includes the supraspinous and interspinous ligaments, as well as the facet joint capsule.

According to the three column scheme, stability is based upon the integrity of two of the three spinal columns.

Spinal instability may be inferred when plain radiographs demonstrate a loss of 50 percent of vertebral height or

excessive kyphotic angulation around the fracture [29]. The angle is determined by the intersection of two lines, one

measured along the superior endplate of the vertebral body one level above the fracture and the other along the

inferior endplate of the vertebral body one level below [30]. Compression fractures with greater than 30 degrees and

burst fractures with greater than 25 degrees angulation are generally considered unstable. The presence of a

neurologic deficit also indicates spinal instability, since the spinal column has failed to protect the spinal cord [31].

Few studies have been performed to validate the three column scheme. In a biomechanical study of cadaveric

human spines, researchers found the middle column to be the major determinant of spine stability when axial or

flexion stress was applied [32].

TL injuries can be divided into four basic patterns: wedge compression fractures, stable and unstable burst

fractures, flexion-distraction injuries, and translational injuries. All of these fractures result from one or more of three

mechanisms of injury: axial compression, axial distraction, and translation [28,33]. A widely used classification for

TL spinal column injury combines a distinction between major and minor fracture patterns using the three column

scheme and the five injury patterns.

In 2005, the Spine Trauma Study Group introduced a classification system for thoracolumbar injuries called the

Thoracolumbar Injury Classification and Severity Score (TLICS). This score assigns numerical values to each injury

based upon morphology, neurologic status, and integrity of the posterior ligamentous complex, which includes the

supraspinous ligament, interspinous ligament, ligamentum flavum, and facet joint capsules [34]. Scoring of the

TLICS is as follows:

Injury morphology

Compression = 1 point

Burst = 1 point

Translational/rotational = 3 points

Distraction = 4 points

Neurological Status

Intact = 0 points

Nerve root = 2 points

Cord, conus medullaris:

Incomplete = 3 points

Complete = 2 points

Cauda equina = 3 points

Posterior Ligament Complex

Intact = 0 points

Injury suspected/indeterminate = 2 points

Injured = 3 points

The total numerical score is used to guide treatment. A score ≥5 suggests instability and the need for operative

treatment, whereas a score ≤3 suggests stability. A score of 4 is considered indeterminate and either operative or

conservative management may be indicated [35].

Compression fractures — Wedge, or anterior, compression fractures account for 50 to 70 percent of all TL

fractures [33,36]. They usually result from compressive failure of the anterior column under an axial load applied in

flexion. Injuries that do not disrupt the posterior ligament complex are stable. An additional rotational force is

necessary to cause an unstable fracture pattern. If there is severe compression (>50 percent of vertebral height),

significant fracture kyphosis (>30 degrees), a rotational component to the injury, or compression fractures at

multiple levels, then the posterior ligamentous complex may fail and progress to involve the middle column,

resulting in spinal instability (image 22). Fractures with any of these characteristics or a TLICS score ≥4 warrant

imaging with CT. Fracture kyphosis is described above. (See 'TL spinal column injury classification' above.)

Compression fractures that exhibit between 10 and 40 percent compression are managed on a case-by-case basis

in consultation with a spine surgeon. Neurologic findings or concomitant injuries warrant a thorough evaluation.

Management of spinal column injury is discussed separately. (See "Evaluation and acute management of cervical

spinal column injuries in adults".)

Simple wedge fractures demonstrate less than 10 to 30 percent compression and generally cause no neurologic

impairment, since the middle column remains intact (image 23). These fractures generally result from falls, motor

vehicle crashes, and occasionally generalized tonic-clonic seizures [37]. Associated injuries are common and

fractures frequently occur at other spinal levels.

Simple wedge compression fractures are best seen on lateral radiographs, which demonstrate anterior compression

of the vertebral body without disruption of the posterior cortex. The AP radiograph may demonstrate a subtle

increase in the interspinous distance if there is a kyphotic deformity.

It is important to confirm that the posterior elements remain intact (ie, no vertebral subluxation), since the integrity

of the posterior cortex is what distinguishes the stable wedge compression fracture from the unstable burst fracture.

Standard radiographs may not be adequate to evaluate the integrity of the posterior vertebral cortex.

In an analysis of 67 thoracolumbar radiographs reviewed by two radiologists and two orthopedists, 20 percent of CT-

confirmed burst fractures were initially misdiagnosed as wedge fractures [38]. Thus, CT should be performed when

plain radiographs suggest any possible involvement of the posterior cortex in what appears to be a wedge

compression fracture. Such findings include fracture lines that extend into the posterior cortex and any

compression of the posterior cortex. Other suggestive features include loss of posterior vertebral height and

widening of the interpedicular distance.

Burst fractures — Burst fractures comprise approximately 14 percent of all TL injuries [36]. They are caused by

compressive forces that fracture the vertebral endplate and pressure from the nucleus pulposus upon the vertebral

body (image 24 and image 25). Spinal cord injury from retropulsion of bony fragments into the spinal canal can

occur.

Burst injuries can occur with or without injury to posterior elements; posterior element involvement increases the

risk for neurologic deficits [37]. Burst fractures are most commonly associated with falls and motor vehicle

collisions. All burst fractures should be considered unstable, since neurologic deficits are seen in 42 to 58 percent

of patients [36].

Burst fractures can be difficult to visualize and are often misdiagnosed by plain radiography because posteriorly

displaced bone fragments often lie at the level of the pedicles [39]. Lateral x-rays of burst fractures may

demonstrate a loss of anterior and posterior vertebral height, and may show a distorted posterior longitudinal

ligament line. AP radiographs may demonstrate a widening of the interpedicular distance (>1 mm difference

between the vertebrae above and below).

Unstable burst fractures are often misdiagnosed as stable anterior wedge fractures. In one retrospective trial, 6

experienced radiologists correctly identified only 30 of 39 burst fractures among 53 thoracolumbar radiographs

reviewed [40]. We recommend that a CT be obtained if there is vertebral compression greater than 50 percent or a

burst fracture is suspected for any reason.

Flexion-distraction (lap belt) injuries — Flexion-distraction injuries account for 10 percent of all TL spinal

column injuries and occur most frequently in patients wearing only a lap belt (ie, no chest restraint) during vehicular

trauma [41]. While neurologic deficits are rare, associated intraabdominal injuries, such as small and large

intestinal perforations, are more common. A seat belt sign may be present. (See "Initial evaluation and

management of blunt abdominal trauma in adults".)

Chance fractures are representative of TL flexion-distraction injury (image 26 and image 27). Classically the patient

is wearing only a lap belt, positioned incorrectly above the pelvic bones. Sudden deceleration during a collision

causes forceful flexion at the lap belt, leading to compressive failure of the anterior and middle columns and a tear

in the posterior longitudinal ligament. Chance fractures are often misdiagnosed as compression fractures. Pure

ligamentous disruptions also occur and account for 10 to 25 percent of flexion-distraction injuries [37].

In contrast to the cervical region, where articular processes are small, flat, and almost horizontal, articular

processes in the lumbar region are large, curved, and nearly vertical, and thus, unilateral facet dislocations are rare.

Instead, one or both articular processes fracture, and the upper vertebra swings forward, resulting in an unstable

fracture-dislocation pattern.

Radiographic findings of flexion-distraction injuries include compression fractures of the vertebral body, and

increased posterior interspinous spaces caused by distraction. A characteristic finding is increased length of the

vertebral segment as a result of distraction. Displacement is unusual, since the mechanism does not involve a

significant rotational or translational component.

Flexion-distraction injuries may be missed on routine axial CT scans since the disruption is oriented in the

horizontal plane. Thus, it is important to obtain sagittal reconstructions of CT images if a lap belt mechanism is

known or a flexion-distraction injury is suspected for other reasons (eg, presence of abdominal seat belt sign,

known bowel injury) [11]. A systematic review found that reformatted CT images from visceral studies demonstrated

greater sensitivity and specificity than plain TL radiographs in detecting spinal column injury [42].

Translational spinal column injury — Massive direct trauma to the back can cause failure of all three columns of

the TL spine resulting in translational injuries. Several injury patterns can occur, including rotational fracture-

dislocations, shear injuries, and pure vertebral dislocations. The thoracolumbar junction (T10 to L2) is the most

common site [43]. Patients with a complete vertebral dislocation from massive trauma almost invariably

demonstrate neurologic deficits.

Among patients rendered paraplegic from TL trauma, the majority have sustained a fracture-dislocation injury

(image 28 and image 29). Approximately 26 to 40 percent of these result in permanent neurologic deficits [43].

Most patients also sustain multiorgan system trauma.

Shear fractures and pure dislocations result in severe neurologic injury, causing complete paraplegia in nearly all

patients. Pure dislocations appear as a complete displacement of the superior vertebrae relative to the one below.

Fracture fragments created by shearing forces may lodge in the spinal canal. CT scan is helpful in evaluating these

injuries because it quantifies the extent of spinal cord impingement.

Other TL fracture patterns — Minor spinal fracture patterns account for 14 percent of all TL injuries and include

isolated transverse process fractures (image 30 and image 31), spinous process fractures (image 32), facet or

laminar fractures, bipedicular fractures, and fractures of the pars interarticularis. Most minor spinal fractures occur

in the lumbar region and are caused by direct blows. Sudden contraction of the psoas muscles can result in

avulsion of a transverse process.

While transverse process fractures are considered stable, in high velocity trauma they frequently do not occur in

isolation. In one retrospective analysis of 28 patients who initially appeared to have isolated transverse process

fractures by plain x-ray, three patients were subsequently found to have compression and burst fractures by CT

scan [44]. High thoracic spinous process fractures may be associated with brachial plexus injury, while lumbar and

sacral spinous process fractures may cause lumbosacral plexus injury. To ensure appropriate diagnosis and

management of spinal column injury, a CT should be obtained when transverse process fractures are seen on plain

radiographs.

INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, “The Basics” and

“Beyond the Basics.” The Basics patient education pieces are written in plain language, at the 5th to 6th grade

reading level, and they answer the four or five key questions a patient might have about a given condition. These

articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the

Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the

10th to 12th grade reading level and are best for patients who want in-depth information and are comfortable with

some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these

topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on

“patient info” and the keyword(s) of interest.)

Basics topics (see "Patient information: Vertebral compression fracture (The Basics)" and "Patient

information: Neck fracture (The Basics)")

SUMMARY AND RECOMMENDATIONS

Blunt trauma, particularly motor vehicle collisions, accounts for most spinal column injuries. Approximately

three percent of blunt trauma patients sustain such an injury. Elder patients who fall are also at risk. (See

'Epidemiology' above.)

The cervical spine is the most commonly injured part of the spinal column. Within the cervical spine, the

most common sites of injury are around the second cervical vertebra (C2, or axis) or in the region of C5, C6,

and C7. The anatomy of the spinal column and common mechanisms of injury are described in the text.

(See 'Anatomy' above and 'Mechanisms' above.)

The degree of stability is perhaps the most important feature of any spinal column injury. The stability of

common spinal injuries is described in the text and summarized in the accompanying table (table 1). (See

'Cervical spinal column injury' above and 'Thoracic and lumbar (TL) spinal column injury' above.)

Differences in the structure and location of the cervical and thoracolumbar portions of the spinal column lead

to different types of injuries, although there is some overlap. The cervical spinal column is susceptible to a

wide range of fractures, dislocations, and ligamentous injuries. Compression fractures are the most common

injury of the thoracolumbar spinal column.

ACKNOWLEDGMENT — We are saddened by the untimely death of John Marx, MD, who passed away in July

2012. We wish to acknowledge Dr. Marx's dedication and his many contributions to UpToDate, in particular, his

work as editor-in-chief for Emergency Medicine and as a section editor and author for Adult Trauma.

Use of UpToDate is subject to the Subscription and License Agreement.

Topic 357 Version 20.0

GRAPHICS

Spine anatomy overview

(A) This anterior view shows the isolated vertebral column.(B) This right lateral view shows the isolated vertebral column. The isolated vertebrae aretypical of each of the three mobile regions. Note the increase in size of the vertebrae as thecolumn descends.(C) This posterior view of the vertebral column includes the vertebral ends of ribs,representing the skeleton of the back.(D) This medial view of the axial skeleton in situ demonstrates its regional curvatures andits relationship to the cranium (skull), thoracic cage, and hip bone. The continuous, weight-bearing column of vertebral bodies and IV discs forms the anterior wall of the vertebralcanal. The lateral and posterior walls of the canal are formed by the series of vertebralarches. The IV foramina (seen also in part B) are openings in the lateral wall through whichspinal nerves exit the vertebral canal. The posterior wall is formed by overlapping laminaeand spinous processes, like shingles on a roof.Reproduced with permission from: Moore KL, Dalley AF. Clinically Oriented Anatomy, 5th ed, LippincottWilliams & Wilkins, Philadelphia 2006. Copyright © 2006 Lippincott Williams & Wilkins.

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Spine anatomy MRI

This sagittal MRI study shows the primary contents of thevertebral canal. The medullary cone (L. conus medullaris) is thecone-shaped inferior end of the spinal cord, which typically endsat the L1–L2 level in adults. The dura mater, the external overingof the spinal cord (gray), is separated from the spinal cord by afluid-filled space (black) and from the wall of the vertebral canalby fat (white) and thin-walled veins (not visible here).Reproduced with permission from: Moore KL, Dalley AF. Clinically OrientedAnatomy, 5th ed, Lippincott Williams & Wilkins, Philadelphia 2006. Copyright© 2006 Lippincott Williams & Wilkins.

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Basic vertebral anatomy

A "typical" vertebra, represented by L2.(A) Functional components include the vertebral body (bone color), a vertebral arch(red), and seven processes: three for muscle attachment and leverage (blue) and fourthat participate in synovial joints with adjacent vertebrae (yellow).(B, C) Bony formations of the vertebrae are demonstrated. The vertebral foramen isbounded by the vertebral arch and body. A small superior vertebral notch and a largerinferior vertebral notch flank the pedicle.(D) The superior and inferior notches of adjacent vertebrae plus the IV disc that unitesthem form the IV foramen for the passage of a spinal nerve and its accompanyingvessels. Note that each articular process has an articular facet where contact occurswith the articular facets of adjacent vertebrae (B-D).Reproduced with permission from: Moore KL, Dalley AF. Clinically Oriented Anatomy, 5th ed, LippincottWilliams & Wilkins, Philadelphia 2006. Copyright © 2006 Lippincott Williams & Wilkins.

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Cervical vertebrae transverse view

The 3rd-6th cervical vertebrae have a "typical" structure; the 1st,2nd, and 7th are "atypical." Typical vertebrae demonstraterectangular bodies with articular uncinate processes on theirlateral aspects, triangular vertebral foramina, bifid spinousprocesses, and transverse foramina.Reproduced with permission from: Moore KL, Dalley AF. Clinically OrientedAnatomy, 5th ed, Lippincott Williams & Wilkins, Philadelphia 2006. Copyright© 2006 Lippincott Williams & Wilkins.

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C1 and C2 bone anatomy

(A) Observe the occipital condyles that articulate with the superior articular surfaces(facets) of the atlas (vertebra C1).(B) The atlas, on which the cranium rests, has neither a spinous process nor a body. Itconsists of two lateral masses connected by anterior and posterior arches.(C, D) The tooth-like dens characterizes the axis (vertebra C2) and provides a pivotaround which the atlas turns and carries the cranium. It articulates anteriorly with theanterior arch of the atlas ("Facet for dens" in part B) and posteriorly with the transverseligament of the atlas (see part B).Reproduced with permission from: Moore KL, Dalley AF. Clinically Oriented Anatomy, 5th ed, LippincottWilliams & Wilkins, Philadelphia 2006. Copyright © 2006 Lippincott Williams & Wilkins.

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Thoracic vertebrae

(A) T1 has a vertebral foramen and body similar to a cervical vertebra.(B) T5-T9 vertebrae have typical characteristics of thoracic vertebrae.(C) T12 has bony processes and a body size similar to a lumbar vertebra. The planesof the articular facets of thoracic vertebrae define an arc (red arrows) that centers onan axis traversing the vertebral bodies vertically.(D) Superior and inferior costal facets (demifacets) on the vertebral body, costal facetson the transverse processes, and long sloping spinous processes are characteristic ofthoracic vertebrae.Reproduced with permission from: Moore KL, Dalley AF. Clinically Oriented Anatomy, 5th ed, LippincottWilliams & Wilkins, Philadelphia 2006. Copyright © 2006 Lippincott Williams & Wilkins.

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Cervical spine joints and ligaments

(A) The ligaments in the cervical region are shown. Superior to the prominent spinousprocess of C7 (vertebra prominens), the spinous processes are deeply placed andattached to an overlying nuchal ligament.(B) The ligaments in the thoracic region are shown. The pedicles of the superior twovertebrae have been sawn through and the vertebral arches removed to reveal theposterior longitudinal ligament. Intertransverse, supraspinous, and interspinousligaments are demonstrated in association with the vertebrae with intact vertebralarches.Reproduced with permission from: Moore KL, Dalley AF. Clinically Oriented Anatomy, 5th ed, LippincottWilliams & Wilkins, Philadelphia 2006. Copyright © 2006 Lippincott Williams & Wilkins.

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Craniovertebral joints and ligaments

(A) Ligaments of the atlanto-occipital and atlantoaxial joints. The tectorial membraneand the right side of the cruciate ligament of the atlas have been removed to show theattachment of the right alar ligament to the dens of vertebra C2 (axis).(B) The hemisected craniovertebral region shows the median joints and membranouscontinuities of the ligamenta flava and longitudinal ligaments in the craniovertebralregion.Reproduced with permission from: Moore KL, Dalley AF. Clinically Oriented Anatomy, 5th ed, LippincottWilliams & Wilkins, Philadelphia 2006. Copyright © 2006 Lippincott Williams & Wilkins.

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Classification of spinal injuries

Mechanisms of spinal injury Stability

Flexion

Anterior wedge fracture Stable

Flexion teardrop fracture Extremely unstable

Clay shoveler's fracture Stable

Subluxation Potentially unstable

Bilateral facet dislocation Always unstable

Atlanto-occipital dislocation Unstable

Anterior atlantoaxial dislocation with or withoutfracture

Unstable

Odontoid fracture with lateral displacement Unstable

Fracture of transverse process Stable

Flexion-rotation

Unilateral facet dislocation Stable

Rotary atlantoaxial dislocation Unstable

Extension

Posterior neural arch fracture (C1) Unstable

Hangman's fracture (C2) Unstable

Extension teardrop fracture Usually stable in flexion; unstable inextension

Posterior atlantoaxial dislocation with or withoutfracture

Unstable

Vertical compression

Burst fracture of vertebral body Stable

Jefferson fracture (C1) Extremely unstable

Isolated fractures of articular pillar and vertebralbody

Stable

Reproduced with permission from: Marx, JA, Hockberber, RS, Walls, RM. Rosen's emergency medicine:concepts and clinical practice, 6th ed, Mosby, Inc., St. Louis 2006. Copyright ©2006 Elsevier.

Atlanto-occipital disassociation

Severe flexion injuries involving the atlas (C1) can cause anatlanto-occipital dislocation or disassociation.Courtesy of Mary Hochman, MD.

BAI and BDI cervical spine measurements

Powers ratio for cervical spine

Atlanto-axial dislocation

Guide for odontoid cervical spine x-ray

Reproduced with permission from: Mower WR, Hoffman JR, Mahadevan SV. Cervicalspine fractures. In: Harwood-Nuss Clinical Practice of Emergency Medicine, 5th ed,Wolfson AB (Ed), Lippincott Williams & Wilkins, Philadelphia 2009. Copyright ©2009 Lippincott Williams & Wilkins.

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C1 arch fractures: Jefferson fracture

This odontoid or open-mouth view shows a Jefferson fracture.Note the step-off of the lateral masses (white arrow), whichnormally are in alignment.Courtesy of Mary Hochman, MD

C1 arch fractures: Jefferson fracture

This lateral radiograph shows increased predental space betweenC1 and the odontoid (red arrow). Also note the soft tissueswelling anterior to the site of injury.Courtesy of Mary Hochman, MD

Burst (Jefferson) fracture of C1

The Jefferson fracture of C1 is highly unstable and occurs when avertical compression force is transmitted through the occipitalcondyles to the lateral masses of the atlas.

Open mouth (odontoid) view of C1/C2 dislocation

The AP open mouth view of C1/C2 intervertebral joint space and the odontoidreveals an obvious offset of the right lateral mass of C1 (white arrow) over thecorresponding lateral mass of C2. There is more subtle malalignment of left C1lateral mass (red arrow) relative to C2. These findings suggest a Jefferson fractureof C1.Courtesy of Richard Waite, MD

C1 posterior neural arch fracture

A posterior neural arch fracture of C1 results from compressionof the posterior elements between the occiput and the spinousprocess of C2 during forced neck extension. A vertical fractureline through the posterior neural arch is seen on this lateral x-ray(white arrow).Courtesy of Mary Hochman, MD

C2 pedicle fractures: Hangman's fracture

Traumatic spondylolysis of C2 (so-called "hangman's fracture") isan unstable injury that occurs when the cervicocranium (theskull, atlas, and axis functioning as a unit) is thrown into extremehyperextension.Courtesy of Mary Hochman, MD

Pedicle fracture of C2 (axis)

Odontoid fracture type II

Type II odontoid fractures are the most common type and occur at thebase of the odontoid process where it attaches to C2. They areconsidered unstable.Courtesy of Mary Hochman, MD

Odontoid fractures

Odontoid fracture type III

Type III odontoid fractures travel through the upper portion of the bodyof C2. They are mechanically unstable, since they allow the dens and theocciput to move as a unit.Courtesy of Mary Hochman, MD

Cervical anterior wedge fracture: Lateral view

Anterior wedge fractures result from extreme flexion. Spinalinstability can occur with severe anterior wedge fractures (loss ofover half the vertebral height) or multiple adjacent wedgefractures.Courtesy of Mary Hochman, MD

Cervical anterior wedge fracture

Courtesy of Mary Hochman, MD

Anterior wedge fracture of the cervical spine

Cervical vertebral body fractures: Flexion tear drop fracture

A flexion teardrop fracture results when severe flexion causes a vertebralbody to collide with the one below, leading to anterior displacement of awedge-shaped fragment (resembling a teardrop).Courtesy of Mary Hochman, MD

Flexion teardrop fracture of the cervical spine

Cervical extension teardrop fracture

The extension teardrop fracture occurs when abrupt neckextension causes the anterior longitudinal ligament to pull theanteroinferior corner away from the remainder of the vertebralbody, producing a triangular-shaped fragment (red arrow).Courtesy of Mary Hochman, MD

Extension teardrop fracture of the cervical spine

Spinous process fractures: Clay shoveler's fracture

The clay shoveler's fracture is an isolated fracture of one of thespinous processes of the lower cervical vertebrae. It is a stableinjury that most often occurs with direct trauma to the spinousprocess.Courtesy of Mary Hochman, MD

C7 burst fracture and C6 flexion teardrop

Vertical compression injuries such as burst fractures occur in the cervicalspine when axial loads are exerted on the spine. When the nucleuspulposus of the intervertebral disk is forced into the vertebral body, thebody shatters outward, resulting in a burst fracture. Note the fracturefragment on the CT image above (white arrow) that is displaced into thespinal canal.Courtesy of Mary Hochman, MD

Bilateral laminar fractures of cervical spine

Lateral radiograph (A) demonstrates posterior impaction with multiple comminutedlaminar and spinous processes fractures from C2 to C6 (white arrows). The acutevacuum disc (black arrow) with abnormal widening of the anterior C6-7 disc space is asign of anterior and middle column distraction. The corresponding CT images (B andC) demonstrate displacement of the spinous processes and bilateral comminutedlaminar fractures (white arrows).Reproduced with permission from: Schwartz ED, Flander AE. Spinal Trauma: Imaging, Diagnosis, andManagement, Lippincott Williams & Wilkins, Philadelphia 2007. Copyright © 2007 Lippincott Williams& Wilkins.

Bilateral facet dislocations (C4/C5)

Bilateral facet dislocations occur when flexion forces extendanteriorly, causing the inferior articulating facets of the uppervertebra to pass over the superior facets of the lower vertebra.Complete spinal cord injury most often results.Courtesy of Mary Hochman, MD

Bilateral facet dislocations

These CT images show a bilateral facet dislocation (red arrows) at theC6-C7 level.Courtesy of Mary Hochman, MD

Unilateral facet dislocation (C5/C6)

Unilateral facet dislocations involve flexion and rotation. Rotation occurs aroundone of the facet joints; dislocation occurs at the contralateral facet joint, withthe superior facet moving over the inferior facet. In the CT images above notethe normal juxtaposition of the facets on the right and the dislocation on theleft.Courtesy of Mary Hochman, MD

Cervical spine unilateral facet dislocation with bow tie sign

The plain x-ray of the cervical spine in the lateral projection revealsunilateral malalignment of the facets of C3 (red arrows) comparedwith subjacent column which are widely separated resulting in thebow tie appearance of the posterior elements as they line up (D,red overlay). Associated mild subluxation is present. The yellowarrows show normal alignment of the facet joints of C4, C5, andC6. These findings are reminiscent of a unilateral facet dislocation.

Three columns of the thoracolumbar spine

Reproduced with permission from: Jankowitz BT, Welch WC, Donaldson III WF. Injuries to the spinalcord and spinal column. In: The Trauma Manual, 3rd ed, Peitzman AB (Ed), et al, Lippincott Williams& Wilkins, Philadelphia, 2007. Copyright © 2007 Lippincott Williams & Wilkins.

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Plain x-ray of thoracic compression fracture with kyphosis

The patient is a 55-year-old female who fell and presented with back pain. The plainx-ray of the thoracic spine in the AP (A) and lateral (B) projections reveal acompression fracture of T5 (red arrows) with about 70 percent loss of height of thevertebral body. A second compression fracture of T7 (white arrows) has resulted inabout 15 percent loss of height of the vertebral body. The fractures are betterappreciated on the lateral examination in both instances. A kyphosis of the thoracicspine of about 30 degrees has resulted. Associated findings include mild osteopeniaand chronic fractures of the left sided ribs 3, 4, 5, and 6.Courtesy of Richard Waite, MD

Mild compression fracture of second lumbar vertebra

The x-rays of the lumbar spine in the AP (A) and lateralprojections (B), and magnified view of the lateral view (C), reveala mild compression fracture of the superior endplate of L2 (redarrow). The white arrow shows a near normal appearing L2 in theAP projection with normal interpedicular distance. Note the step-off deformity of the anterior and superior aspect of the endplateof L2 (yellow arrow) which is a manifestation of the injury. Thereis less than 20 percent loss of vertebral height.

Lumbar burst fracture

Anteroposterior (A) and lateral (B) radiographs demonstrating a L3burst fracture with retropulsion of bony fragments into the spinalcanal noted on an axial CT image (C).Reproduced with permission from: Whang PW, Vaccaro AR. Fractures anddislocations of the thoracolumbar spine. In: Rockwood and Green's Fractures inAdults, 7th ed, Bucholz RB, (ed), Lippincott Williams & Wilkins, Philadelphia 2010.Copyright © 2010 Lippincott Williams & Wilkins.

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Vertebral burst fracture of the lumbar spine: Plain radiograph

The x-rayx are from a 37-year-old female drug addict who jumped from a buildingin a suicide attempt. The plain x-rays in lateral projection (A) and AP projection (B)of the lumbar spine show a burst fracture of L1 characterized by loss of height andmalposition of the L1 vertebral body with posterior retropulsion into the spinalcanal (white arrow). The posterior elements are splayed as reflected in thewidening of the pedicles (red arrows).Reproduced with permission from: Frymoyer JW, Wiesel SW, et al. The Adult and Pediatric Spine.Lippincott Williams & Wilkins, Philadelphia 2004. Copyright © 2004 Lippincott Williams & Wilkins.

Chance fracture of the lumbar spine

The plain film of the lumbar spine in the lateral projection shows atransverse fracture of the third lumbar (L3) vertebral body. Chance fractureis often due to seatbelt injury. Note the wide radiolucent gap between thetwo fracture segments (black arrows). Associated fractures of the lamina,pedicles and interspinous ligament has splayed the posterior elements(white arrow).

Lumbar spinous process and vertebral body fractures

A lateral radiograph of the lumbar spine (A, magnified in B). The 54-year-old malesustained hyperflexion injury with distraction resulting in a transverse fracturethrough the T12 spinous process (white arrowhead) and a compression fracture ofthe vertebral body (blue arrow).Courtesy of Robert Ward, MD.

Thoracolumbar fracture-dislocation radiograph

Anteroposterior (A) and lateral (B) radiographs of a T12-L1 fracture-dislocation.Reproduced with permission from: Whang PW, Vaccaro AR. Fractures and dislocationsof the thoracolumbar spine. In: Rockwood and Green's Fractures in Adults, 7th ed,Bucholz RB, (ed), Lippincott Williams & Wilkins, Philadelphia 2010. Copyright © 2010Lippincott Williams & Wilkins.

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X-ray shear fracture T12

The plain x-ray of the thoracolumbar spine in AP (A and B) andlateral projections (C and D) reveals a fracture dislocationcentered around T11/T12. The red arrows define the spinousprocesses on the frontal film and demonstrate the abruptangulation centered at the dislocated level. The yellow arrowspoint to the posterior cortices of the vertebral bodies andhighlight the extent of abnormal translation.Courtesy of Richard Waite, MD.

X-ray fracture of lumbar transverse process

The plain film tomogram of the left sided transverse processes ofthe lumbar spine in the AP projection reveals transverse fracturesof the L3 and L4 vertebra (arrows).Reproduced with permission from: Yochum TR, Rowe LJ. Yochum and Rowe'sEssentials of Skeletal Radiology, 3rd Edition. Lippincott Williams & Wilkins,Philadelphia 2004. Copyright © 2004 Lippincott Williams & Wilkins.

CT transverse process fracture

The CT scan of lumbar spine in the transverse projection reveals an acuteincomplete fracture of the left transverse process (arrow).

Thoracic spinous process fracture

The radiograph of the thoracolumbar spine in lateral projection(A, and magnified in B) reveals an equivocal abnormality of thespinous process of T12. A CT scan using sagittal reformatting(C) and transverse projection (D) are more convincing forfractures through the spinous process of T11 (white arrowhead)and T12 (small white arrow). A fracture of a left sided 11th rib isof incidental note.Courtesy of Gregory Waryasz, MD.