Flexion and Extension Views of C-spine

- See:
      - Anterior Subluxation:
      - Ligamentous Instability:

- Discussion:
    - the flexed view is usually most helpful in detecting ligamentous injury that is not apparent on the neutral view
    - determines the integrity of the supporting soft tissues and ligaments, as well as the stability of a known injury
           - subluxations may be the sequelae of ligamentous tears w/o frxs;
           - this malalignment may only be apparent w/ the dynamic study;
    - typically, this view is ordered at 7 to 10 days post injury when C-spine is less tender;

- Flexion View:
    - ADI in children should be less than 3.5 mm;
    - ADI in adults should be less than 3 mm;
    - alignment of cervical canal should assume gentle kyphosis
    - interspinous and interlaminar distances should remain symmetric, while facet joint & intervetebral spaces should not widen;
    - vertebral body angulation / translation:
         - patterns of instability include:
                - 1.7 mm or greater of disk widening;
                - 3.5 mm of translational displacement (vetebral body subluxation should be no greater than 1 mm as compared to extension view);
                - angulation between two adjacent vertebra of 11 deg more than contiguous cervical vertebrae;
                - measurements are made from each inferior endplate;

- Extension View:
    - mild lordosis;
    - as result of compression and rotation compenents, there is unilateral articular pillar frx, subluxation of contralateral facets, disruption of 
         anterior longitudinal ligament, & mild anterior displacement of the involved body;

- Assessment of RA:
    - need to observe any abnormal movements of the
C1-C2 level;
    - distance > 3mm between anterior arch of Atlas & front of odontoid process is abnormal as is a distance of 3-5 mm between posterior 
           borders of adjacent subaxial vertebrae;

- Contraindications:
    - altered state of consciousness (closed head injury, intoxication, or combativeness);
    - documented neurologic deficit;
    - inability of patient to flex and extend the neck w/o assistance;

- Technique:
    - views are aligned identical to the lateral of the cervical spine
    - patient flexes and extends their own neck under the supervision of the requesting physician;
    - no manual flexion/extension should be applied;
    - adequate amount of flexion is necessary for test to be meaningful;
    - support head w/ lead-gloved hand or small pillow after flexed posture is actively achieved by the patient in the supine position

Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Thursday, December 22, 2011 12:58 pm