ABSTRACT
Objective:To investigate the value of three-dimensional (3D) CT in diagnosing cricoarytenoid dislocation.Methods:From January 2021 to December 2021, 31 patients with unilateral cricoarytenoid dislocation who had been treated by reduction forceps at the Affiliated BenQ Hospital of Nanjing Medical University were collected retrospectively, and their voice recovered or improved significantly after therapy. The preoperative CT images were reconstructed by volume rendering (VR). The dislocated side (left and right), type of dislocation (total dislocation and subluxation), and dislocation direction (anterior, posterior, internal and external dislocation) of cricoarytenoid dislocation were observed. According to arytenoid articular surface of cricoid cartilage exposed completely or not (caused by arytenoid displacement), they were divided into complete dislocation and subluxation. According to the direction of arytenoid displacement and the part of arytenoid articular surface of cricoid cartilage exposed, they were divided into anterior, posterior, internal and external dislocation. According to the shape of the vocal cords on laryngoscope, anterior and posterior dislocation of each case was judged, and then compared with that of CT.Results:On VR images, there were 28 cases of cricoarytenoid subluxation (90.3%, 28/31) and 3 cases of complete dislocation (9.7%, 3/31). Left cricoarytenoid dislocation was 26 cases (83.9%, 26/31) and right cricoarytenoid dislocation was 5 cases (16.1%, 5/31). Posterior dislocation was 28 cases (90.3%, 28/31) and anterior dislocation was 3 cases (9.7%, 3/31). There were 23 cases of internal dislocation (74.2%, 23/31), 2 cases of external dislocation (6.4%, 2/31), and 6 cases without obvious internal and external dislocation (19.4%, 6/31). Three cases of complete dislocation were left posterior internal dislocation.There were 24 cases of left posterior dislocation (77.4%, 24/31), 4 cases of right posterior dislocation (12.9%, 4/31), 2 cases of left anterior dislocation (6.4%, 2/31) and 1 case of right anterior dislocation (3.2%, 1/31). On laryngoscope, there were 19 cases of posterior dislocation (61.3%, 19/31), 9 cases of anterior dislocation (29.0%, 9/31), 3 cases were difficult to assess (9.7%, 3/31) because of aryepiglottic fold covering. Sixteen cases (55.2%, 16/28) were consistent with 3D CT, and 12 cases (42.8%, 12/28) were inconsistent.Conclusion:The 3D CT is a reliable method to evaluate cricoarytenoid dislocation, which can show dislocated side, type and direction of cricoarytenoid dislocation clearly.