Medial tibial plateau sustaining higher physiological stress than the lateral plateau: based on 3D printing and finite element method

Abstract

Background Medial compartment knee osteoarthritis (KOA) accounts for most KOA cases, and increased trabecular bone volume fraction (BV/TV) is one of the pathological changes in the tibial plateau of KOA. How BV/TV changes before and after the menopause and its effects on medial compartment KOA are yet to be clarified. Methods Twenty femurs from twenty 12-week-old rats were included. The operated group underwent ovariectomy (to represent the osteoporosis condition), called the O group, and the non-operated group was the normal control, called the N group. Micro-CT scans of the femoral condyles were acquired 12 weeks after the surgery, and the volume of interest (VOI) of medial-, inter-, and lateral-condyle trabeculae were three-dimensional (3D) printed for uniaxial compression mechanical test and simulated by the finite element (FE) method. Results The results demonstrated that the O group indicated poorer trabecular architecture than the N group in three parts of the femoral condyle, especially in the intercondyle. Within the group, the BV/TV, trabecular thickness (Tb.Th), and trabecular number (Tb.N) ratios between the medial and lateral condyles were greater than 1 in both N and O groups. The medial condyle trabeculae's mechanical properties were higher than those of the lateral condyle, and this superiority appears to be broadened under osteoporotic conditions. FE modelling well reproduced these mechanical differentiations. Conclusions According to Wolff's law, the higher BV/TV and mechanical properties of the medial femoral condyle may be due to inherent imbalanced loading on the knee component. Alterations in BV/TV and their corresponding mechanical properties may accompany KOA.

3D printed trabeculae conditionally reproduce the mechanical properties of the actual trabeculae - A preliminary study

“…They concluded that 3D printing is an important complement for FE analysis to evaluate the mechanical properties of trabecular structures that do not physically exist. In our latest study ( Zheng et al., 2022 ), we also combined 3D printing and FE models to prove that the medial tibial plateau sustains higher physiological stress than the lateral plateau. This result helps explain why varus knee deformities account for the majority of patients with knee osteoarthritis (KOA) and affect more than 70% of patients with idiopathic KOA, as well as the “nonuniform settlement” phenomenon of the medial tibial plateau.…”

PSD95 as a New Potential Therapeutic Target of Osteoarthritis: A Study of the Identification of Hub Genes through Self-Contrast Model

“…This model reduces potential confounding factors, providing a valuable tool for investigating the biological causes of human knee OA and identifying therapeutic interventions [14]. The primary distinguishing factor between this model's control and degeneration groups is the different mechanical stress experienced by cartilage in the LTP and MTP [15,16]. In OA, the cartilage in the MTP is exposed to high levels of mechanical overloading [17,18].…”