Identification of the site of posterior glottic adhesion and exclusion of cricoarytenoid joint ankylosis using both CT and functional laryngeal ultrasound

Abstract

We experienced a case in which a detailed diagnosis of posterior glottic adhesion (PGA) was made using a combination of computed tomography (CT) and functional laryngeal ultrasound (FLUS). CT revealed PGA and identified its location. In contrast, FLUS excluded cricoarytenoid joint (CAJ) ankylosis. There was a limited opening of the left arytenoid cartilage (AC). CT revealed ossification of the left AC, with ossification extending to the medial side of the left CAJ. In addition, a hemispherical soft mass protruded from the site of ossification in the medial part of the CAJ towards the medial part of the larynx. The protruding lesion was localized to the posterior wall of the left subglottic portion, with a basal area of approximately 8 mm². It was suggested that the AC was in an adducted position due to this portion and that it was adherent to the cricoid cartilage. We performed FLUS from the low-ossified area of the lamina of the thyroid cartilage. FLUS confirmed the rotation, rocking, and gliding motions of the left AC, and the hypothesis of CAJ ankylosis was rejected. Based on these results, we concluded that there was no joint ankylosis; however, the perichondral tissue on the medial side of the AC body was adherent. The patient then underwent voice therapy. Although the restricted vocal fold opening did not improve, glottic closure improved and hoarseness was reduced.