Biomechanical characterisation of equine laryngeal cartilage

• Published in: Equine veterinary journal 2011-09, Vol.43 (5), p.592-598
• Main Authors: PASSMAN, S. N., CHEETHAM, J., BONASSAR, L. J., DUCHARME, N. G., RAWLINSON, J. J.
• Format: Article
• Language: English
• Subjects: Airway management; Animals; arytenoid; Biomechanical Phenomena; Biomechanics; cricoid; equine larynx; Female; geometry; horse; Horses; Horses - anatomy & histology; Horses - physiology; hyaline cartilage; Laryngeal Cartilages - anatomy & histology; Laryngeal Cartilages - physiology; Larynx; Male; material properties
• ISSN: 0425-1644; 2042-3306
• DOI: 10.1111/j.2042-3306.2010.00315.x

Summary Reasons for performing the study: Upper airway obstruction is a common problem in the performance horse as the soft tissues of the larynx collapse into the airway, yet there is a paucity of information on biomechanical properties for the structural cartilage components. Objective: To measure the geometry and compressive mechanical properties of the hyaline cartilage to improve understanding of laryngeal function and morphology. Methods: A total of 11 larynges were harvested from Thoroughbred and Standardbred racehorses. During gross dissection, linear dimensions of the cricoid were obtained. From both the cricoid and arytenoid, specimens were cored to obtain 6 mm disc samples from 3 sites within the dorsal cricoid (caudal, middle and rostral) and 2 central sites in the arytenoids (inner, outer). The specimens were mechanically tested using radial confined compression to calculate the aggregate modulus and permeability of the tissue. The biomechanical data were analysed using a nested mixed effects model. Results: Geometrically, the cricoid has relatively straight walls compared to the morphology of human, ovine and canine larynges. There were significant observations of higher modulus with increasing age (0.13 MPa per year; P = 0.007) and stiffer cricoid cartilage (2.29 MPa) than the arytenoid cartilage (0.42 MPa; P