On the State of Stress in the Growth Plate under Physiologic Compressive Loading

Abstract

The growth plate is a thin layer of cartilage sandwiched between epiphyseal and metaphyseal bone and is the location of active bone growth during childhood. It is subjected to large compressive and shear forces while protecting its resident chondrocytes from damage. We believe that computational modeling can help us better understand how the macro-scale loads are transmitted to micro-scale stresses and strains within the growth plate cartilage. As a first step in this process we analyzed the mechanical response of compression experiments performed on bovine bone/growth plate/bone samples. We endeavored to estimate the modulus of elasticity of the growth plate itself by simulating the compression experiments of these specimens using the finite element method. It is shown that when the growth plate in the compression specimens was modeled as a flat layer, the state of stress in the cartilage was triaxial and non-uniform with the hydrostatic stress being much greater than the octahedral shear stress over most of the central region of the growth plate test samples.