Arytenoid Subluxation Workup

Updated: Aug 06, 2020
  • Author: Joshua S Schindler, MD; Chief Editor: Arlen D Meyers, MD, MBA  more...
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Laboratory Studies

See the list below:

  • Currently, no laboratory studies help in the diagnosis of arytenoid subluxation (AS).


Imaging Studies

See the list below:

  • CT scan

    • Several reports have identified high-resolution CT scan as extremely helpful in diagnosing arytenoid subluxation (AS), with the following caveat: Although positive results from the CT scan may be helpful in confirming AS, nondiagnostic CT scan results do not rule out AS.

    • Typical findings of AS include displacement of the arytenoid body, altered angulation of the aryepiglottic fold, and widening of the ventricle on the affected side.

    • The relationship of the arytenoid to the cricoid cartilage is the imaging parameter that best distinguishes AS from vocal fold paralysis. CT scan images can demonstrate a slight rotation and displacement of the arytenoid in persons with vocal fold paralysis, but not to the degree that is evident in persons with AS.

    • CT scans may be of limited usefulness if the laryngeal cartilages are insufficiently mineralized, especially in the pediatric population.

    • Helical CT scanning has been developed in some centers as a more accurate tool in the evaluation of cricoarytenoid joint integrity. [8]

  • MRI

    • MRI has also emerged as a helpful study for the diagnosis of AS. MRI offers the benefit of direct sagittal imaging compared with the reconstructions provided by CT scan. Generally, MRI is superior to CT scan for imaging soft tissue interfaces.

    • To date, MRI has not been shown to be more effective than CT scan in the evaluation of the arytenoid-cricoid interface. MRI has not supplanted CT scan as the primary imaging modality for laryngeal structures.


Other Tests


Laryngeal videostroboscopy

Videostroboscopy is also a useful study in the workup of arytenoid subluxation (AS), allowing the clinician to detect malalignment of the true vocal folds, which is noted in persons with AS. Differences in vocal fold level as small as 1 mm can be detected.

Videostroboscopy can also detect the slightest motion of the true vocal fold, arytenoid cartilage, and surrounding structures. These findings can help to distinguish AS from recurrent laryngeal paralysis.

Videostroboscopy helps detect other injuries. Submucosal vocal fold hemorrhage, hemorrhagic polyps, and cysts can result in vocal fold scarring if not diagnosed and properly treated. Videostroboscopy remains invaluable in the identification of these often subtle injuries.

Laryngeal electromyography

EMG of the laryngeal musculature is very important in the diagnostic workup of suspected AS. EMG findings can help to confirm normal innervation of the larynx in patients with vocal fold immobility, thereby distinguishing AS from recurrent laryngeal nerve paralysis.

Evidence of innervation includes the presence of voluntary electrical activity in the laryngeal muscles on the immobile side and the presence of recruitment.

The aforementioned literature review by Frosolini et al found that, among the studies looked at, laryngeal EMG played a fundamental role in eliminating unilateral vocal fold paralysis as a differential. [4]


Diagnostic Procedures

See the list below:

  • Direct laryngoscopy

    • Prior to the development of imaging techniques and the application of laryngeal EMG, direct laryngoscopy was the standard diagnostic and therapeutic modality for arytenoid subluxation (AS).

    • Direct laryngoscopy under general anesthesia with palpation of the arytenoid cartilage yields valuable clinical information.

    • The cricoarytenoid joint is assessed for mobility and displacement of the arytenoid.

    • Current diagnostic aids allow the clinician to have a more accurate diagnosis before proceeding to surgery.