The joint capsule of the cricoarytenoid joint - Biomechanical and clinicalaspects.

Background: Impaired movement of the cricoarytenoid joint with hoarseness a nd immobility of the vocal ligament may occur as a consequence of laryngeal trauma and joint disease. Little is known to date about the cricoarytenoid joint capsule and its role in joint pathology. Methods: The present study analyses the structure of the cricoarytenoid joint capsule by means of hist ological, immunohistochemical, and scanning electron microscopical methods. Investigations are performed on larynges of 17 male and 16 female. Results : The cricoarytenoid joint was found to be lined by a wide and lax joint ca psule consisting of a fibrous and a synovial membrane. The capsule was stre ngthened posteriorly by the cricoarytenoid ligament. As like the fibrous me mbrane the cricoarytenoid ligament consisted mainly of collagen types I and ill. Moreover the ligament was found to be rich in elastic fibers. Unexpec ted large and intensively vascularized synovial folds projected into the jo int cavity. Conclusion: The capsule of the cricoarytenoid joint can be comp ared with the joint capsules of the limbs despite its structure and its inv olvement in joint pathology. Based on the laxity of the joint capsule it wa s concluded that invasive interventions at the respiratory tract with dislo cation of the arytenoid cartilage can lead to incarceration of the synovial folds. After a trauma aerosynovitis or formation of hemarthrosis may occur , with subsequent fixation of the arytenoid in an abnormal position.