New approach to diagnose arytenoid dislocation and subluxation using three-dimensional computed tomography

Area of Science:

• Otolaryngology
• Anatomy
• Medical Imaging

Background:

• Accurate diagnosis of arytenoid dislocation (AD) and arytenoid subluxation (AS) relies on understanding the complex 3D anatomy of the arytenoid cartilage.
• Distinguishing AD/AS from unilateral vocal fold paralysis (UVFP) is crucial for appropriate patient management.

Purpose of the Study:

• To analyze the 3D arrangement and movement patterns of the arytenoid cartilage in patients with AD/AS using 3D computed tomography (3DCT).
• To establish diagnostic criteria differentiating AD/AS from UVFP based on the position and mobility of the muscular process (MP).

Main Methods:

• Retrospective analysis of 2 AD, 10 AS, and 23 UVFP cases.
• Generation of 3D computed tomography (3DCT) images during rest and phonation.
• Classification of AD/AS positions into four joint regions: mediocaudal, laterocaudal, mediocranial, and laterocranial.
• Focus on the position and movement of the muscular process (MP) for joint assessment.

Main Results:

• Dislocated MPs in AD/AS cases were localized to mediocaudal, mediocranial, and laterocranial regions.
• AD was diagnosed by complete joint separation; AS and severe UVFP showed partial MP displacement outside the cricoid facet.
• Key differentiation: UVFP MPs were medial and lateral, while AS MPs were unilateral.
• Absence of passive gliding movements in AD/AS, unlike UVFP.

Conclusions:

• 3D CT imaging of the muscular process (MP) position and movement provides characteristic findings for diagnosing arytenoid dislocation (AD) and arytenoid subluxation (AS).
• Distinct MP localization (unilateral in AS vs. medial/lateral in UVFP) and lack of passive gliding are key differentiators.
• Complete joint separation confirms AD, while specific positional and movement patterns aid in diagnosing AS versus UVFP.