Arytenoid Dislocation as a Cause of Prolonged Hoarseness after Cervical Discectomy and Fusion

摘要

Study Design Case series of two arytenoid dislocations after anterior cervical discectomy. Objective To recognize arytenoid dislocation as a possible cause of prolonged hoarseness in patients after anterior cervical discectomies. Summary of Background Data Prolonged hoarseness is a common postoperative complication after anterior cervical spine surgery. The etiology of prolonged postoperative hoarseness is usually related to a paresis of the recurrent laryngeal nerve. However, other causes of postoperative hoarseness may be overlooked in this clinical scenario. Other possible etiologies include pharyngeal and laryngeal trauma, hematoma and edema, injury of the superior laryngeal nerve, as well as arytenoid cartilage dislocation. Arytenoid dislocation is often misdiagnosed as vocal fold paresis due to recurrent or laryngeal nerve injury. Methods We report two cases of arytenoid dislocation and review the literature on this pathology. Results Two patients treated with anterior cervical discectomy and fusion experienced prolonged postoperative hoarseness. Arytenoid dislocation was confirmed by flexible fiber-optic laryngoscopy in both cases. The dislocations experienced spontaneous reduction at 6 weeks and 3 months postsurgery. Conclusions Arytenoid dislocation must be considered in the differential diagnosis of prolonged postoperative hoarseness and evaluated for using direct laryngoscopy, computed tomography, or a laryngeal electromyography. Upon diagnosis, treatment must be considered immediately. Slight dislocations can reduce spontaneously without surgical intervention; however, operative intervention may be required at times. Keywords: arytenoid dislocation, prolonged hoarseness, anterior cervical discectomy Hoarseness is a common postoperative complication, reported in ～50% of cases requiring intubation. 1 In 1.6% of such cases, this hoarseness will not resolve after the first week and may continue indefinitely. 1 The etiology of prolonged postoperative hoarseness is often difficult to establish; it can be caused by pharyngeal and laryngeal trauma, hematoma and edema, injury to the recurrent or superior laryngeal nerves, as well as arytenoid cartilage dislocation. 2 3 4 Postoperative hoarseness due to arytenoid dislocation is often misdiagnosed as recurrent laryngeal nerve (RLN) palsy. Arytenoid dislocations are reported in nearly 0.1% of all surgeries requiring intubation and must be carefully considered during a postoperative evaluation. Arytenoid dislocation can be caused by intubation, external blunt trauma, laryngoscopy, as well as any acute trauma to the cricoarytenoid joint. 5 Intubation is the most common etiology. Arytenoid dislocation results in a hypomobile vocal cord complex, which can be readily observed via strobovideolaryngoscopy, laryngeal electromyography (EMG), or computed tomography (CT). Treatment commonly includes closed reduction and chemical splinting, and spontaneous reduction can also occur. 3 5 We present two cases of arytenoid dislocation after anterior cervical discectomy and fusion (ACDF). This complication has not yet been reported in anterior cervical discectomy cases.