Descriptive anatomy of the cricoarytenoid articulation: application to articular dynamics in carcinology

The descriptive anatomy of the cricoarytenoid articulation provides an esse ntial foundation for understanding disorders of mobility of the larynx, esp ecially in carcinology. Thirteen formaline-preserved anatomic specimens of the adult larynx were studied and 4 pathologic larynges with loss of mobili ty due to a malignant tumor. The cricoid and arytenoid articular surfaces s howed major intra- and inter-individual variations, causing dynamic asymmet ry at the glottic level. They were joined by a connective-elastic articular capsule bounding a cavity, characterized by a peudo-meniscal synovial ridg e and deep peripheral blind recesses, indicative of great articular mobilit y. The cricoarytenoid ligament shares in stabilizing the articulation. The posterior cricoarytenoid m. (abductor) and the lateral cricoarytenoid m. (a dductor) have a motor innervation derived from the inferior laryngeal nerve , which forms an endolaryngeal arch with a ventral concavity, in contact wi th the lateral articular recess. The cricoarytenoid articulation thus appea rs as a diarthrosis possessing three degrees of liberty during movements of glottic abduction and adduction: an antero-posterior rocking movement, an antero-medial shift of the arytenoid on the cricoid, and a less marked axia l rotation. Histological study of the cricoarytenoid articulation where mob ility was reduced by carcinomatous infiltration showed that each articular component may be affected (muscles, cartilage, capsule, nerve), and that se veral components may be involved simultaneously to a minimal degree. The th erapeutic implications are important, particularly in conservative laryngea l surgery.