TY - JOUR
T1 - Modeling the mechanical behavior of vertebral trabecular bone
T2 - Effects of age-related changes in microstructure
AU - Silva, Matthew J.
AU - Gibson, L. J.
N1 - Funding Information:
AcknowledgmeTnhtse: h elpfulc ommentosf Mary Bouxseina ndRalph Mueller of the OrthopedicB iomechanicLsa b at Beth Israel Deaconess Medical Centera nd ProfessorM ary Boyce of MIT are gratefullya c-knowledgedT. his study was supportedb y grantsf rom the National ScienceF oundatio(nE ID-9023692a)n dthe NationaIln stituteosf Health (AR41894-0182b),y the Maurice E. Mueller Professorshiipn Biome-chanicsa t HarvardM edicalS chool,a ndthe Harry and Evelyn Indursky and familyO rthopediBc iomechanicLsa boratorya t Beth IsraelD eacon-ess MedicalC enter.
PY - 1997/8
Y1 - 1997/8
N2 - Age-related reductions in the thickness and number of trabeculae in vertebral trabecular bone have been documented by several workers, yet the relative effects of these changes on mechanical properties are not known. We developed a two-dimensional model of human vertebral trabecular bone and investigated its mechanical behavior using finite element analysis. The stress-strain behavior, failure mode, and strain distributions predicted using the model were consistent with those observed for vertebral trabecular bone under compressive loading. Random reductions in the number of trabeculae reduced the modulus and strength of the models two to five times more than uniform reductions in the thickness of trabeculae that caused the same loss of bone volume. For example, randomly removing longitudinal trabeculae to achieve a reduction in density of 10% reduced the strength by approximately 70%, whereas removing the same amount of bone by uniformly reducing the thickness of the longitudinal trabeculae only reduced the strength by approximately 20%. For a simulation of aged bone, in which the thickness and number of trabeculae were reduced concurrently, the strength was 23% of its intact ('young') value. When the bone mass of the aged model was restored to its intact level by increasing the thickness but not the number of trabeculae, the strength increased by 60%, but was still only 37% of its intact value. These combined findings, based on a two-dimensional, idealized model of vertebral trabecular bone, illustrate the importance of maintaining trabecular number and suggest that it may not be possible to restore bone strength following a period of advanced bone loss if a substantial number of trabeculae have been resorbed. Thus, until treatments exist that can increase trabecular number, the most effective treatment strategy is to prevent the degradation of bone strength by maintaining the number of trabeculae at a healthy level.
AB - Age-related reductions in the thickness and number of trabeculae in vertebral trabecular bone have been documented by several workers, yet the relative effects of these changes on mechanical properties are not known. We developed a two-dimensional model of human vertebral trabecular bone and investigated its mechanical behavior using finite element analysis. The stress-strain behavior, failure mode, and strain distributions predicted using the model were consistent with those observed for vertebral trabecular bone under compressive loading. Random reductions in the number of trabeculae reduced the modulus and strength of the models two to five times more than uniform reductions in the thickness of trabeculae that caused the same loss of bone volume. For example, randomly removing longitudinal trabeculae to achieve a reduction in density of 10% reduced the strength by approximately 70%, whereas removing the same amount of bone by uniformly reducing the thickness of the longitudinal trabeculae only reduced the strength by approximately 20%. For a simulation of aged bone, in which the thickness and number of trabeculae were reduced concurrently, the strength was 23% of its intact ('young') value. When the bone mass of the aged model was restored to its intact level by increasing the thickness but not the number of trabeculae, the strength increased by 60%, but was still only 37% of its intact value. These combined findings, based on a two-dimensional, idealized model of vertebral trabecular bone, illustrate the importance of maintaining trabecular number and suggest that it may not be possible to restore bone strength following a period of advanced bone loss if a substantial number of trabeculae have been resorbed. Thus, until treatments exist that can increase trabecular number, the most effective treatment strategy is to prevent the degradation of bone strength by maintaining the number of trabeculae at a healthy level.
KW - Aging
KW - Finite element analysis
KW - Mechanical properties
KW - Microstructural model
KW - Osteoporosis
KW - Vertebral trabecular bone
UR - https://www.scopus.com/pages/publications/0030869475
U2 - 10.1016/S8756-3282(97)00100-2
DO - 10.1016/S8756-3282(97)00100-2
M3 - Article
C2 - 9267695
AN - SCOPUS:0030869475
SN - 8756-3282
VL - 21
SP - 191
EP - 199
JO - Bone
JF - Bone
IS - 2
ER -