Effects of preexisting microdamage, collagen cross-links, degree of mineralization, age, and architecture on compressive mechanical properties of elderly human vertebral trabecular bone.
Previous studies have shown that the mechanical properties of trabecular bone are determined by bone volume fraction (BV/TV) and microarchitecture. The purpose of this study was to explore other possible determinants of the mechanical properties of vertebral trabecular bone, namely collagen cross-link content, microdamage, and mineralization. Trabecular bone cores were collected from human L2 vertebrae (n = 49) from recently deceased donors 54-95 years of age (21 men and 27 women). Two trabecular cores were obtained from each vertebra, one for preexisting microdamage and mineralization measurements, and one for BV/TV and quasi-static compression tests. Collagen cross-link content (PYD, DPD, and PEN) was measured on surrounding trabecular bone. Advancing age was associated with impaired mechanical properties, and with increased microdamage, even after adjustment by BV/TV. BV/TV was the strongest determinant of elastic modulus and ultimate strength (r²  = 0.44 and 0.55, respectively). Microdamage, mineralization parameters, and collagen cross-link content were not associated with mechanical properties. These data indicate that the compressive strength of human vertebral trabecular bone is primarily determined by the amount of trabecular bone, and notably unaffected by normal variation in other factors, such as cross-link profile, microdamage and mineralization.
INSERM U831, University of Lyon, Lyon F-69008, France. helene.follet@inserm.fr
Helene
H
Follet
Stéphanie
S
Viguet-Carrin
Brigitte
B
Burt-Pichat
Baptiste
B
Dépalle
Yohann
Y
Bala
Evelyne
E
Gineyts
Francoise
F
Munoz
Monique
M
Arlot
Georges
G
Boivin
Roland D
RD
Chapurlat
Pierre D
PD
Delmas
Mary L
ML
Bouxsein
D000368:Aged; D000369:Aged, 80 and over; D000596:Amino Acids / Q000378:metabolism; D001120:Arginine / Q000031:analogs & derivatives / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D002113:Calcification, Physiologic / Q000502:physiology*; D003094:Collagen / Q000378:metabolism*; D019245:Compressive Strength; D003432:Cross-Linking Reagents / Q000378:metabolism*; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000378:metabolism / Q000473:pathology*; D008239:Lysine / Q000031:analogs & derivatives / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D013314:Stress, Mechanical; D016474:Weight-Bearing
D000596:Amino Acids; D015415:Biomarkers; D003432:Cross-Linking Reagents; C015484:pyridinoline; C036020:deoxypyridinoline; D003094:Collagen; D001120:Arginine; C062187:pentosidine; D008239:Lysine