[Spontaneous dislocation of the arytenoid cartilage].

Dislocation of the arytenoid cartilage occurs following medical instrumentation involving the laryngeal cavity or laryngeal injury from outside the larynx. We reported a case of spontaneously posterior dislocation of the arytenoid cartilage. A 53 year-old man suffering from suddenly recurring aphonia and its improvement many over 3 months without laryngeal injury or inducement eventually ceased to improve. Laryngoscopic findings showed that the left vocal fold was tensely prolonged and the vocal process of the arytenoid cartilage on the left side was dislocated posterolaterally. X-ray videofluorography of the larynx on repetitive phonation of /he/ showed abnormally high and diagonal displacement of the vocal fold and the upper structure of the arytenoid cartilage on the left side. Palpating the cricoarytenoid joint on the left side showed abnormal swelling with tenderness. Electomyography of the intrinsic laryngeal muscle on the left side showed normal action potential. From these findings, we diagnosed his voice disorder as spontaneously posterior dislocation of the arytenoid cartilage. We manually reduced it by pulling up a balloon inserted from the piriform sinus of the affected side to the esophagus.