Vulnerability to rupture of the intact articular surface with respect to age and proximity to site of fibrillation: a dynamic and static-investigation.
Bovine cartilage-on-bone samples taken from healthy mature patellae and from the intact regions of degenerate patellae were subjected to dynamic and static compressive loading. In-plane articular surface strain and rupture behavior were investigated and compared with previously published data obtained from immature bovine patellae. Both aging and proximity of the intact tested region to the fibrillated lesion increase the likelihood of articular surface rupture under both impact and static loading. Substantially higher levels of stress can be applied dynamically than statically without increasing the risk of articular surface rupture. Articular surface rupture is a result of lineal strains generated by the indentation profile, but any direct measurement of its in situ rupture strength is not possible. However, differences in both measured articular surface strains and rupture characteristics between the three categories of tissue suggest that there is a progressive reduction in the intrinsic strength of the intact surface layer of cartilage with both aging and proximity to site of fibrillation.
Flachsmann
René
R
Biomaterials Laboratory, Department of Chemical and Materials Engineering, University of Auckland, New Zealand.
Kim
Woong
W
Broom
Neil
N
D000375:Aging / Q000502:physiology*; D000818:Animals; D001842:Bone and Bones / Q000473:pathology; D002358:Cartilage, Articular / Q000473:pathology*; D002417:Cattle; D012421:Rupture / Q000473:pathology*; D013314:Stress, Mechanical