Stress rate and creep behaviors of cancellous bone under uniaxial compression / 中国组织工程研究

ABSTRACT

BACKGROUND: Cancellous bone, as an important part of bone, is a kind of porous, inhomogeneous, anisotropic and viscoelastic structure, which plays a critical role in load transmission and energy absorption. Therefore,research on its mechanical properties is of great significance.OBJECTIVE: To investigate the compressive properties of cancellous bone at different stress rates and its creep behaviors at different stress levels.METHODS: The fresh cancellous bone from pig femur was used as the material, and subjected to different stress until the compressive strain of sample was up to 5%. The constant compressive stress levels were loaded on the surface of cancellous bone for 7200 s to observe its creep behaviors.RESULTS AND CONCLUSION: (1) In the uniaxial compression test, the stress values and Young's modulus increased with the stress rate increasing under the same strain value. (2) The stress-strain curves of cancellous bone were different at different loading rates, indicating that the mechanical properties of cancellous bone depend on the loading rate. (3) In the creep test, the creep strain increased with the increase of stress level, but the creep compliance decreased with the increase of stress level. (4) These results suggest that the stress rate and stress level have significant influence on compressive properties of cancellous bone, which provide reference for avoiding cancellous bone injury.