Importance of Material Properties and Porosity of Bone on Mechanical Response of Articular Cartilage in Human Knee Joint—A Two-Dimensional Finite Element Study

Abstract

Mechanical behavior of bone is determined by the structure and intrinsic, local material properties of the tissue. However, previously presented knee joint models for evaluation of stresses and strains in joints generally consider bones as rigid bodies or linearly elastic solid materials. The aim of this study was to estimate how different structural and mechanical properties of bone affect the mechanical response of articular cartilage within a knee joint. Based on a cadaver knee joint, a two-dimensional (2D) finite element (FE) model of a knee joint including bone, cartilage, and meniscus geometries was constructed. Six different computational models with varying properties for cortical, trabecular, and subchondral bone were created, while the biphasic fibril-reinforced properties of cartilage and menisci were kept unaltered. The simplest model included rigid bones, while the most complex model included specific mechanical properties for different bone structures and anatomically accurate trabecular structure. Models with different porosities of trabecular bone were also constructed. All models were exposed to axial loading of 1.9 times body weight within 0.2 s (mimicking typical maximum knee joint forces during gait) while free varus-valgus rotation was allowed and all other rotations and translations were fixed. As compared to results obtained with the rigid bone model, stresses, strains, and pore pressures observed in cartilage decreased depending on the implemented properties of trabecular bone. Greatest changes in these parameters (up to -51% in maximum principal stresses) were observed when the lowest modulus for trabecular bone (measured at the structural level) was used. By increasing the trabecular bone porosity, stresses and strains were reduced substantially in the lateral tibial cartilage, while they remained relatively constant in the medial tibial plateau. The present results highlight the importance of long bones, in particular, their mechanical properties and porosity, in altering and redistributing forces transmitted through the knee joint.

A computational algorithm to simulate disorganization of collagen network in injured articular cartilage

“…Unconfined compression geometry did not include subchondral bone. However, based on recent clinical and computational studies (Hart et al 1991;Venäläinen et al 2014Venäläinen et al , 2016, bone could be important to consider when simulating the physiological environment of cartilage as changes in subchondral bone density and plate thickness might alter the strain and stress distribution in cartilage, thus, possibly contributing to the changes in the collagen network structure in injured cartilage during the progression of OA. In addition, depth-wise and spatial variation in the material properties and composition of cartilage might affect slightly to the simulation results, especially if they are changed during the reorientation process.…”

Elucidating the role of size of hydroxyl apatite particles toward the development of competent antiosteoporotic bioceramic materials: In vitro and in vivo studies

“…60 Osteoporosis affects all these properties of the bone. 60 Osteoporosis affects all these properties of the bone.…”

“…Mechanical behavior of a bone is determined by the structure, intrinsic, and local properties of the materials. 60 Osteoporosis affects all these properties of the bone. Authors have studied the effect of osteoporosis and treatment on mechanical properties of the bone.…”

The Factors Causing Knee Joint Strain in Sports and the Prevention

“…When walking, the maximum axial force is 2.3~7.1 times of the weight of tibia, patella joint force in normal gait is 0.2~1.8 times of the weight, but in running or jumping it can be increased to about 11 times of the weight. Stress is larger, easy to produce the articular cartilage of the acute injury and chronic injury, femoral condyle and tibial condylar structure [4,5]. The main function of the knee joint is flexion and extension movement.…”