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

Abstract

Understanding the complex three-dimensional (3D) arrangement of the arytenoid cartilage is necessary for diagnosing arytenoid dislocation (AD) and arytenoid subluxation (AS). We examined the 3D arrangements of AD and AS (AD/AS) cases by region and considered their new diagnoses. This retrospective study included 2 patients with AD, 10 with AS, and 23 with unilateral vocal fold paralysis (UVFP) for comparison. The etiologies were intubation-induced and idiopathic. We classified the AD/AS position into four joint regions: mediocaudal, laterocaudal, mediocranial, and laterocranial. We generated 3D computed tomography (3DCT) images during rest and phonation to analyze functional movements. We attempted to compare the endoscopic findings and 3DCT images of patients with UVFP and AD/AS. To examine the joint status, we especially focused on the position and movements of the muscular process (MP) on the joint because the arytenoid facet is mainly located on the back of the MP. We were able to obtain endoscopic and 3DCT findings characteristic of each AD/AS region. The dislocated MPs were localized to the mediocaudal, mediocranial, and laterocranial regions. Two AD cases were diagnosed due to complete separation of the joint surfaces during rest and phonation. The finding of MPs displacing partially outside the cricoid facet is common to both severe UVFP and AS. The most important differentiation point was that the MP in UVFP cases was located on both the medial and lateral side regions of the joint, but that of AS was on one side region only. Furthermore, no cases of passive gliding movements characteristic of UVFP that have been described previously by us were observed in AD/AS cases. AD can be diagnosed by findings of complete joint separation. AS can be diagnosed based on positions and movements distinct from those of UVFP.

Analysis of High-Pitched Phonation Using Three-Dimensional Computed Tomography

“…We previously divided the cricoid facet into cranial and caudal parts along the cylindrical long axis of the facet. 9,10 Notably, if the arytenoid cartilage glided caudally, it moved anteriorly at the same time. First, we examined the position of the arytenoid cartilage of the CAJ during comfortably pitched phonation to compare that during the high-pitched phonation.…”

“…In 3DCT studies of unilateral vocal fold paralysis (UVFP), we also reported that the arytenoid cartilage on the healthy side moved toward the medial (during phonation) and lateral (during rest) parts of the CAJ in a rocking movement, and that the arytenoid cartilage was located toward the caudal part of the CAJ during both rest and phonation. 9,10 However, the normal state of phonation is not necessarily being observed because the opposite side is paralyzed and the arytenoid cartilage on the healthy side is likely to be overadducted during phonation. Additionally, many issues remain unclear, such as how the presence of a gliding movement in the arytenoid cartilage as a result of a change in the phonation condition (eg, high-pitched phonation) affects vocal fold elongation.…”

“…6 However, we used three-dimensional CT (3DCT) to study the movement of the arytenoid cartilage and its aid in the diagnosis and treatment. [7][8][9][10] By taking images at appropriate times during phonation and setting thresholds for each, it is possible to construct reproducible 3D images.…”

Pediatric Voice and Swallowing Disorders Related to Vocal Fold Immobility: the Use of Laryngeal EMG

“…Reduced vocal fold mobility, vocal fold high mismatch, vocal fold length differences, an absent Bjostle^sign and arytenoid edema are all suggestive of arytenoid dislocation [15]. A CT with fine cuts through the larynx can also be helpful [16]. Definitive diagnoses can be made with laryngeal EMG and palpation of the arytenoid under suspension laryngoscopy [14••].…”

Experimental Study on 3D Chi - Hap Scaffolds for Thyroid Cartilage Repairing

“…Autologous tissue, allogeneic, artificial materials and tissue engineering technology were utilized to repair and reconstruct laryngeal cartilage damage [3]. At present, natural macromolecule biomaterials, synthetic polymer materials, bioceramic materials and composites have been the primary materials for tissue engineering scaffolds [4][5][6][7][8]. Natural biological materials possess excellent adhesion for cells, hydrophilicity and compatibility, which include gelatin, sodium alginate, collagen, chitosan, and fibrin gels.…”