A musculoskeletal finite element model of rat knee joint for evaluating cartilage biomechanics during gait

Abstract

Abnormal loading of the knee due to injuries or obesity is thought to contribute to the development of osteoarthritis (OA). Small animal models have been used for studying OA progression mechanisms. However, numerical models to study cartilage responses under dynamic loading in preclinical animal models have not been developed. Here we present a musculoskeletal finite element model of a rat knee joint to evaluate cartilage biomechanical responses during a gait cycle. The rat knee joint geometries were obtained from a 3-D MRI dataset and the boundary conditions regarding loading in the joint were extracted from a musculoskeletal model of the rat hindlimb. The fibril-reinforced poroelastic (FRPE) properties of the rat cartilage were derived from data of mechanical indentation tests. Our numerical results showed the relevance of simulating anatomical and locomotion characteristics in the rat knee joint for estimating tissue responses such as contact pressures, stresses, strains, and fluid pressures. We found that the contact pressure and maximum principal strain were virtually constant in the medial compartment whereas they showed the highest values at the beginning of the gait cycle in the lateral compartment. Furthermore, we found that the maximum principal stress increased during the stance phase of gait, with the greatest values at midstance. We anticipate that our approach serves as a first step towards investigating the effects of gait abnormalities on the adaptation and degeneration of rat knee joint tissues and could be used to evaluate biomechanically-driven mechanisms of the progression of OA as a consequence of joint injury or obesity.

The application of human medical image-based finite element analysis in the construction of mouse osteoarthritis models

“…To address this issue, the FEA method was used to digitally reconstruct the knee joint model of ACL injury, and to compare the stress on articular cartilage under various working conditions with that of normal knee tissue. It further demonstrates the scientificity and feasibility of constructing a knee OA model by ACLT method [ [27] , [28] , [29] ]. The method is based on the principle that mechanical stress stimulation of articular cartilage caused by external factors contributes to the degeneration of articular cartilage.…”

Joint and tissue mechanics in post-traumatic osteoarthritis: insights from the rat model

“…Regarding the musculoskeletal model, validation of joint contact forces against experimental measures is not feasible, as this would have been too invasive to allow natural gait; however, the estimated values are consistent with what has previously been reported in the literature. The loading conditions used as input for the FE model - more specifically the normalized axial force - were considerably higher than the axial loads used in previous models of the mouse and rat knees, which were not based on species-specific musculoskeletal analysis (2.44 and 0.45 body weight, respectively) 18,20 . Therefore, we need to question the mechanical loading landscape previously reported in the literature.…”

“…FE models have been developed to analyze cartilage deformations (strains) and concentrated loads (stresses). However, these FE models used simplified input data that did not accurately represent real movement, as high-fidelity species-specific movement data are scarce [18][19][20][21] . Musculoskeletal models have been used to describe movement based on joint positions and ground reaction forces (i.e., contact forces between the paw and ground), but relied on markerbased motion capture to describe joint positions 22 .…”

Intra-articular administration of PLGA resveratrol sustained-release nanoparticles attenuates the development of rat osteoarthritis

“…MRI, with its recent advancements, has been extensively used to detect the changes in synovial membrane, subchondral bone marrow and cartilage [ [36] , [37] , [38] , [39] , [40] , [41] ]. The primary outcome measure used in this study was MRI, due to its superior contrast resolution and sensitivity to tissue compositions, as well as it ability to assess cartilage changes in osteoarthritis animal models [ 42 , 43 ]. T1ρ and T2 are important markers for determining the changes in cartilage during early phases of this disease [ 44 , 45 ].…”