Papers by Keyword: Cancellous Bone Tissue

Abstract: The mechanical performance of cancellous bone is characterized using experimental measure of parameters (elastic moduli, permeability, etc.) which apply poroelasticity theory. Poroelastic investigations of bone are being extended to investigations of micro-mechanisms of remodeling processes and transport of metabolic product in bone. To understand physiological and pathological behavior of human skeletal system, the accurate measurement of biomechanical properties for bone is the one of important works. Particularly, the microscopic measurement is very important since the biomechanical behavior at the small scale of bone could be closely related to the remodeling of bone. But microscopic measurement of permeability coefficient which is one of important parameter of poroelasticity theory was never measured. In this study, a small scale permeability testing machine was developed to measure accurate coefficient of microscopic specimen permeability. Total of twenty one cylindrical cancellous specimens with a diameter of 500
from seven fresh male and female lumbar vertebrae (14, 39, 59, 61, 69, 75, and 77 years) were fabricated using a micro-milling machine having a resolution of 10
. To determine the directional permeability, bone coordinate was set to be x1 (longitudinal axis) and others were set as x2 (posteroanterior axis) and x3 (latero-medial axis). The measured mean permeability (± SD) values of each direction from x1 to x3 were 9 5.56 10− × (S.D. ± 10 7.10 10− × ), 9 6.66 10− × (S.D. ± 10 6.56 10− × ), and 9 7.04 10− × (S.D. ± 10 8.47 10− × ) m2/Pa/sec, respectively. Mean value in the x1 direction of specimens were the smallest (p<0.01) in comparison to x2 and x3 directions.

Abstract: Multi-directional mechanical properties of human cancellous bone tissue were never measured using a compressive test with microscopic cubic specimens. In this study, a small scale compressive testing machine with nano meter resolution and a measurement system for Poisson’s ratio with sub-nano meter resolution were developed to measure accurate microscopic mechanical properties of human CBT. The measured mean longitudinal (E1), postero-anterior (E2), and lateromedial (E3) elastic moduli were 3.47 GPa (S.D. ±0.41), 2.57 GPa (S.D. ±0.28), and 2.54 GPa (S.D. ±0.22), respectively. ANOVA showed that the longitudinal elastic modulus (E1) was significantly (p < 0.01) greater than the postero-anterior (E2) and latero-medial (E3) elastic moduli. For Poisson’s ratios, ν12 was significantly (p <0.01) higher than ν23 and ν31.