The posterior cricoarytenoid ligaments and their relationship to the cadaveric position of the vocal cords

Configuration of elastin fibers in the intra- and extra-capsule ligaments of the elderly cricoarytenoid joint

PURPOSE

To define the localization and configuration of the elastic fibers of the cricoarytenoid ligament (CAL) and their relationship with the cricoarytenoid joint (CAJ) capsule.

METHODS

Twenty-four CAJs from twelve cadavers were analyzed using Verhoeff-Van Gieson staining, and immunohistochemistry methods. This is a prospective study.

RESULTS

The CAL was classified into two parts: an extra-capsular anterior-CAL and an intra-capsular posterior-CAL. The both parts contained rich elastic fibers. The elastic fibers of the anterior-CAL were orientated in both anterior-posterior and superior-inferior directions and under a relaxation status, whereas the elastic fibers of the posterior-CAL were arranged in a lateral-medial direction and under a taut status.

CONCLUSIONS

This study defined the fine configuration of the CAL, particularly its elastic fibers, which may help us to better understand the biomechanics of the CAJ motions, and differential diagnosis of CAJ disorders. The results of the study re-confirm that the P-CAL is the key posterior-lateral passive force to limit the mobility of the muscular process of the arytenoid cartilage and stabilize the CAJ, whereas the A-CAL may protect the CAJ from an over superior-lateral-posterior motion.

LEVEL OF EVIDENCE

H/A.

Quantitative Analysis of the Visor-Like Vertical Motion of the Cricoarytenoid Joint in the Living Subject

OBJECTIVES

The cricoarytenoid joint has a loose capsule and large cavity and may allow the arytenoid distanced from the cricoid cartilage. The objective was to quantify vertical motion of the arytenoid cartilage in the living subject.

STUDY DESIGN

This is a prospective study.

METHODS

Axial computed tomography images from 35 healthy subjects and seven patients with unilateral vocal fold paralysis were collected at inspiration and phonation. The perpendicular distance from the arytenoid vocal process (VP) or muscular process (MP) to the cricoid plane was measured and analyzed.

RESULTS

During phonation, the range of the vertical movement of the VP was significantly wider than that of the MP. The vertical motion varies in sides, sexes, and ages. The vertical gaps of the VP and MP between the paralyzed and contralateral sides were about 0.8 mm and 1.5 mm, respectively.

CONCLUSIONS

This study confirms a visor-like downward vertical motion of the arytenoid cartilage during phonation.

Anatomical bases of glottic widening surgery related to arytenoidectomy

Derived from arytenoidectomy, different surgical techniques have been developed for widening the glottis in cases of bilateral vocal cord paralysis. Their anatomical bases were reinvestigated in plastinated serial sections of 25 adult human larynges. At the anterolateral surface of the arytenoid cartilage, blood vessels crossing the crista arcuata may cause bleeding complications. The arytenoid cartilage is related to three major histologic complexes which must be taken into account during surgery. The dense connective tissue complex consists of the cricoarytenoid ligament and the conus elasticus, which are connected ventrocaudally. The cricoarytenoid ligament and the vocal cord are separated by the cartilaginous inscription of the vocal process. The muscular complex consists of the transverse arytenoid muscle, which is the posterior wall of the glottis, and the thyroarytenoid muscle, which is intimately fixed to the conus elasticus near the arytenoid cartilage. The loose connective tissue complex is represented by the vestibular fold, containing adipose tissue, mucous glands, few collagenous fiber septa, and at its posterior end, a small cranial extension of the vocal cord. For glottic widening surgery, the arytenoid cartilage must be regarded as an integrated component of an extended fibro-cartilaginous framework supporting the laryngeal airway. Shrinking processes of the dense connective tissue elements may complicate surgical interventions. Iatrogenic lesions of the posterior glottis should be avoided to prevent the development of synechia or insufficient closure of the larynx during swallowing.