title: The contribution of the perichondrium to the structural mechanical behavior of the costal-cartilage.
abstract: The costal-cartilage in the human ribcage is a composite structure consisting of a cartilage substance surrounded by a fibrous, tendon-like perichondrium. Current computational models of the human ribcage represent the costal-cartilage as a homogeneous material, with no consideration for the mechanical contributions of the perichondrium. This study sought to investigate the role of the perichondrium in the structural mechanical behavior of the costal-cartilage. Twenty-two specimens of postmortem human costal-cartilage were subjected to cantilevered-like loading both with the perichondrium intact and with the perichondrium removed. The test method was chosen to approximate the cartilage loading that occurs when a concentrated, posteriorly directed load is applied to the midsternum. The removal of the perichondrium resulted in a statistically significant (two-tailed Student's t-test, p< or =0.05) decrease of approximately 47% (95% C.I. of 35-58%) in the peak anterior-posterior reaction forces generated during the tests. When tested with the perichondrium removed, the specimens also exhibited failure in the cartilage substance in the regions that experienced tension from bending. These results suggest that the perichondrium does contribute significantly to the stiffness and strength of the costal-cartilage structure under this type loading, and should be accounted for in computational models of the thorax and ribcage.
authors.affiliation: Center for Applied Biomechanics, University of Virginia, 1011 Linden Avenue, Charlottesville, VA 22902, USA. jlf3m@virginia.edu
authors.forename: Jason L
authors.initials: JL
authors.lastname: Forman
authors.forename: Eduardo
authors.initials: E
authors.lastname: del Pozo de Dios
authors.forename: Carlos Arregui
authors.initials: CA
authors.lastname: Dalmases
authors.forename: Richard W
authors.initials: RW
authors.lastname: Kent
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D002356:Cartilage / Q000502:physiology*; D005260:Female; D006801:Humans; D051457:Hyaline Cartilage / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D012272:Ribs / Q000502:physiology