Hypergravity stimulates mechanical behavior and micro-architecture of tibia in rats.

Introduction: The bone tissue is susceptible to hypergravity (+ G) environment. It is necessary to discuss the extent to which specific + G values are beneficial or detrimental to bone tissue. The objective of this study was to characterize the effects of high + G values on mechanical properties, microstructures, and cellular metabolism of bone.

Mechanical behavior of a titanium alloy scaffold mimicking trabecular structure.

Background: Additively manufactured porous metallic structures have recently received great attention for bone implant applications. The morphological characteristics and mechanical behavior of 3D printed titanium alloy trabecular structure will affect the effects of artificial prosthesis replacement. However, the mechanical behavior of titanium alloy trabecular structure at present clinical usage still is lack of in-depth study from design to manufacture as well as from structure to mechanical function.

Effects of creep and creep-recovery on ratcheting strain of articular cartilage under cyclic compression.

Since the accumulations of ratcheting strain combined with creep deformation, which are produced in normal activities, can accelerate the fatigue damage of cartilage in joint, the creep-ratcheting and creep-recovery-ratcheting behaviors of articular cartilage are experimentally investigated under creep-fatigue loads. The effect of pre-creep on ratcheting behavior of cartilage was probed firstly and it is found that the initial ratcheting strain of cartilage presents the larger value (30% and 35%) due to its pre-creep deformation in spite of the short pre-creep time applied. With the increasing pre-creep time the ratcheting strain of sample increases while the ratcheting strain rate decreases.

An adaptation model for trabecular bone at different mechanical levels.

Background: Bone has the ability to adapt to mechanical usage or other biophysical stimuli in terms of its mass and architecture, indicating that a certain mechanism exists for monitoring mechanical usage and controlling the bone's adaptation behaviors. There are four zones describing different bone adaptation behaviors: the disuse, adaptation, overload, and pathologic overload zones. In different zones, the changes of bone mass, as calculated by the difference between the amount of bone formed and what is resorbed, should be different.