Cricoarytenoid dislocation is a complication that is more likely to cause doctor-patient disputes, often involving general surgery, thoracic surgery and anesthesiology, most often involving general surgery and anesthesiology, because it is usually a procedure involving the gastrointestinal tract under general anesthesia, and after awakening, symptoms such as hoarseness and choking are present, and then ENT consultation is requested. Cricoarytenoid dislocation is a relatively rare complication of tracheal intubation, with an incidence of about 1 per 1,000. Crico-arytenoid dislocation includes total dislocation of the arytenoid cartilage and subluxation. Crico-arytenoid subluxation refers to the loss of the normal anatomical position of the arytenoid cartilage ring surface in the joint capsule, but there is still partial contact with the arytenoid surface of the cricoid cartilage, which is usually caused by mild laryngeal injury. Total dislocation of the crico-arytenoid joint refers to the complete separation of the arytenoid cartilage from the cricoid cartilage and is usually caused by a severe laryngeal injury. The incidence of cricoarytenoid dislocation is generally considered to be low, mainly because many cricoarytenoid dislocations have been missed or misdiagnosed as recurrent laryngeal nerve palsy due to the constraints of diagnosis and lack of awareness among general surgeons and anesthesiologists in the past. Most scholars believe that cricoarytenoid dislocation can be caused by tracheal intubation (poor exposure of the vocal cords during intubation, violent intubation, repeated intubation and patient agitation during anesthesia or awakening, violent choking and failure to deflate the balloon during extubation), gastric tube insertion, laryngoscopy and neck trauma. If the tip of the arytenoid bone is snapped into the end of the tube during tracheal intubation, it causes anterior subluxation under the force of forward and downward direction. If part of the gas remains in the balloon during extubation, the balloon is squeezed posteriorly and superiorly against the cricoarytenoid joint, resulting in posterior dislocation. Clinical manifestations The main clinical manifestations are hoarseness, a few with subpharyngeal pain, bilateral dislocation may have a sense of suffocation; also can appear breath sound, speech difficulties, throat discomfort, breathing difficulties and vocal fatigue, serious cases may have difficulty in swallowing, choking and coughing with drinking water. Untimely treatment can have serious consequences. Laryngoscopy reveals restricted and fixed vocal fold movement on the affected side, incomplete vocal fold closure; the arytenoid cartilage is red, swollen, deformed, and protrudes above the vocal fold together with the arytenoid epiglottic fold, concealing the posterior part of the vocal fold. CT is an important reference value for the diagnosis of crico-arytenoid dislocation. It can be manifested as follows: 1. Abnormal position of the arytenoid cartilage. A change in the relative position of the arytenoid cartilage is a direct sign of crico-arytenoid dislocation. Under normal circumstances, both sides of the arytenoid cartilage are basically symmetrical. In anterior dislocation, the size and shape of the arytenoid cartilage on both sides are always asymmetric under each level of CT axial position, and the arytenoid cartilage on the affected side is more anterior than that on the healthy side, and appears and disappears 1~2 levels later than that on the healthy side; the opposite is true in posterior dislocation. When the superior and posterior edges of the cricoid cartilage overlap completely, it can be considered as the standard lateral position, and the normal arytenoid cartilage on both sides should overlap completely. When the crico-arytenoid joint is dislocated, the affected arytenoid cartilage is displaced anteriorly or posteriorly, resulting in the lateral image where the arytenoid cartilage on both sides cannot overlap completely. 2.Vocal cord fixation. When the arytenoid cartilage is dislocated, the position of the vocal folds on the affected side is fixed in the CT axial and vocal fold volume reconstruction images under two states of calm breathing and Valsalva breathing, mostly in the paramedian position, and the vocal fissure is asymmetrical and cannot be closed, while the vocal folds on the healthy side are normal inward and outward, or even compensated to the affected side. 3. Abnormal changes of the pyriform fossa. Whether the arytenoid cartilage is dislocated anteriorly or posteriorly, the arytenoid folds are thickened and displaced inward, resulting in asymmetry of the pear-shaped fossa on both sides, and the affected side is obviously enlarged. 4. Abnormal changes of soft tissue. The aryepiglottic folds on the affected side are thickened and shifted inward, and the soft tissues in the interaryepiglottic area are thickened and bulged to different degrees. Diagnosis and differential diagnosis When hoarseness and aphasia occur after tracheal extubation, the possibility of crico-arytenoid dislocation should be thought of, in addition to other common causes. The diagnosis can be made based on the history of intubation, trauma and other clinical manifestations such as hoarseness, laryngoscopy and CT. It must be differentiated from other causes of vocal cord paralysis, mainly by finding the cause. For example, cerebral hemorrhage, cerebral infarction, brain tumor, fracture, nasopharyngeal carcinoma, neck tumor, neck surgery, mediastinal tumor, esophageal cancer, lung cancer, thyroid disease and thyroid surgery, etc. Surface anesthetic drugs can cause temporary dysfunction. Treatment and prognosis The ideal outcome of joint dislocation treatment is to restore the normal anatomical relationship of the joint and to obtain physiological function. Since the cricoarytenoid joint is a sliding joint surrounded by a synovial lined joint capsule, edema and fibrous exudate in the joint cavity after injury can cause joint fixation, which can occur as early as 24-48 hours after injury. The primary treatment for cricoarytenoid dislocation is arytenoid cartilage toggle, a blunt instrumented closed repositioning under visualization, and the outcome of treatment is closely related to the time of consultation. Arytenoid cartilage toggling under surface anesthesia is usually performed, which facilitates the understanding of vocal fold mobility and the degree of improvement in articulation. The significance of toggle repositioning is: to restore the normal anatomical relationship of the joint; to bring the vocal folds to the same level as possible, and to reduce the incomplete closure of the vocal folds. The advantage of the indirect laryngoscopic route is that the toggle surgery is easy to perform as long as the patient extends the tongue and the vocal folds can be fully exposed; however, for patients with long duration of the disease or those who are not satisfied with the long toggle procedure, it is often necessary to perform another toggle surgery. The advantage of the direct laryngoscopic route is that it allows direct observation of the larynx, and it is convenient and easy to perform repeated toggling during the operation, and as long as the operation is standardized, it is easy to reset the larynx successfully in one go. In arytenoid cartilage toggle surgery, the immediate improvement of the patient’s articulatory function is a sign that the surgery may be successful, but it takes time for the voice to return to normal. In fact, toggle repositioning is better under general anesthesia, and the success rate is not very satisfactory. The earlier the toggle procedure is performed, the better; however, this procedure is often subject to surgical circumstances and delayed diagnosis is an important factor in treatment. Some authors have also performed joint capsule steroid injections after extraction, and oral steroid hormone supplementation to facilitate the reduction of swelling in the joint cavity. Generally speaking, patients are not left with sequelae as long as they are treated actively about 1 month after the injury. Individual patients can reset the joint on their own. Tracheal intubation is an important and indispensable part of clinical anesthesia, and complications of cricoarytenoid dislocation can occur in patients with difficult tracheal intubation or in patients with smooth intubation. The main causes of cricoarytenoid dislocation are: (1) unskilled and irregular tracheal intubation, repeated intubation, and rough movements, resulting in direct damage to the arytenoid cartilage from the laryngeal lens and tracheal tube. (2) Excessive insertion of the laryngeal lens and excessive lifting of the laryngoscope may cause dislocation of the arytenoid cartilage and result in the patient’s inability to vocalize. (3) Excessive neck supination during intubation, change of body position, and long anesthesia time, which causes prolonged pressure on the crico-arytenoid joint, is also one of the causes of crico-arytenoid dislocation. (4) Intubation, irritating choking and swallowing movements of the patient during surgery or before extubation can also cause dislocation of the cricoarytenoid joint injury. (5) When removing the tracheal tube, withdrawing the balloon that has not been fully deflated from the voice can cause direct injury. (6) When intubating, the tracheal tube is hard and the distal convex curved part directly damages the cricoarytenoid cartilage. (7) Degeneration of the cricoarytenoid joint in the elderly and decrease in tissue elasticity increase the incidence of cricoarytenoid joint dislocation during tracheal intubation. Cricoarytenoid dislocation is a very rare complication of tracheal intubation, and the key is to prevent it: (1) standardize and gently perform tracheal intubation, (2) moderately expose the voice box and avoid excessive lifting of the laryngoscope. (3) The choice of tracheal tube should be soft and of moderate thickness. (4) Maintain the appropriate depth of anesthesia and avoid violent choking and coughing. (5) Avoid general anesthesia with tracheal intubation in patients who are prone to complications such as cricoarytenoid dislocation with long-term use of glucocorticoids.