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

The descriptive anatomy of the cricoarytenoid articulation provides an essential foundation for understanding disorders of mobility of the larynx, especially in carcinology. Thirteen formaline-preserved anatomic specimens of the adult larynx were studied and 4 pathologic larynges with loss of mobility due to a malignant tumor. The cricoid and arytenoid articular surfaces showed major intra- and inter-individual variations, causing dynamic asymmetry at the glottic level. They were joined by a connective-elastic articular capsule bounding a cavity, characterized by a pseudo-meniscal synovial ridge and deep peripheral blind recesses, indicative of great articular mobility. The cricoarytenoid ligament shares in stabilizing the articulation. The posterior cricoarytenoid m. (abductor) and the lateral cricoarytenoid m. (adductor) have a motor innervation derived from the inferior laryngeal nerve, which forms an endolaryngeal arch with a ventral concavity, in contact with the lateral articular recess. The cricoarytenoid articulation thus appears 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 axial rotation. Histological study of the cricoarytenoid articulation where mobility was reduced by carcinomatous infiltration showed that each articular component may be affected (muscles, cartilage, capsule, nerve), and that several components may be involved simultaneously to a minimal degree. The therapeutic implications are important, particularly in conservative laryngeal surgery.