Cervical Spine

CERVICAL SPINE

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ANATOMY

There are two anatomically distinct regions of the cervical spine: • cervicocranium (C1 and C2)• lower cervical spine (C3 to

C7).

• The atlas (C1) is an osseus ring with two lateral masses that articulate superiorly with the occipital condyles and inferiorly with the axis (C2)

• C1 has no vertebral body. The odontoid process (the dens) projects superiorly from the C2 vertebral body and articulates with the anterior portion of C1. This articulation is maintained by the transverse atlantal ligament.

Each of the lower cervical vertebrae (C3 to C7) consists of a vertebral body, two lateral masses with superior and inferior articular facets, pedicles (connect the lateral masses to the vertebral body), paired laminae, and a spinous process

• The spinal cord is located within the vertebral canal that is made up by the posterior aspect of the vertebral body, the pedicles, and the laminae.

• The transverse processes project laterally from the pedicles. The transverse processes form U-shaped channels for the spinal nerve roots and have a perforation for the vertebral artery.

• The vertebral bodies are joined together by the fibrocartilaginous intervertebral discs. The lateral masses articulate via the facet joints and form lateral supportive columns of the cervical spine.

• Vertebral alignment is maintained by 4 strong ligaments: the anterior longitudinal ligament, the posterior longitudinal ligament, the ligamentum flavum, and the interspinous ligament

WHEN TO ORDER CERVICALSPINE RADIOGRAPHS

• NEXUS LOW-RISK CRITERIA• CANADIAN CERVICAL SPINE RULE

• The NEXUS rule is simpler but the criteria depend more on the subjective assessment of the clinician

• The Canadian rule is more complex but provides more factors to consider in deciding to obtain or omit radiography, such as the mechanism of injury, various low-risk features, and the testing of neck mobility.

The standard cervical spine radiographic series includes three views: (1) lateral view, (2) open mouth view (an AP view of the cervicocranium)(3) AP view of the lowercervical spine

HOW TO READ CERVICAL SPINE RADIOGRAPHS

• Systematic approach provides a stepwise review of importantradiographic landmarks. Such a systematic approach is needed because of the anatomical complexity of the cervical spine and relatively low frequency of injuries. • Targeted approach involves identification of specific injury patterns and enables accurate and efficient radiograph interpretation.

Systematic Approach

Overall Review This uses an ABCS mnemonic device—• assessing the adequacy of the radiograph, • vertebral alignment,• the bones (for fractures or deformity), • cartilage (spaces between adjacent vertebral bodies

and between the spinous processes)• prevertebral soft tissues

A properly performed lateral radiograph demonstrates all seven cervical vertebrae and the C7-T1 interface

CLASSIFICATION OF CERVICAL SPINE INJURIES(Targeted approach)

Hangman’s fractures are classified into three types depending on the degree of displacement• Type I is nondisplaced or minimally displaced (less than 3 mm). This is the most

frequent type (65% of cases) and is the most subtle radiographically. Neurological deficits usually do not occur, which contributes to the risk of missing the injury.

• Type II fractures (28% of cases), the body of C2 is displaced or angulated with respect to C3.

• Type III fractures (7% of cases), the C2–C3 articular facet joints are also disrupted.

When one or both of the fractures involves the posterior portionof the vertebral body rather than the neural arch, the injuryis referred to an “atypical hangman’s fracture.”

TERIMA KASIH