Causes of mechanically induced collagen damage in articular cartilage

Abstract

Osteoarthritis (OA) is a multifactorial disease, associated with articular cartilage degeneration and eventually joint destruction. The phases of the disease have been described in detail, and mechanical factors play an important role in the initiation of OA, but many questions remain about its etiology. Swelling of cartilage, one of the earliest signs of damage, is proportional to the amount of collagen damage. This strongly suggests that damage to the collagen network is an early event in cartilage degeneration. The goal of this study was to determine the mechanical cause of early collagen damage in articular cartilage after mechanical overloading. Both the shear strain along the fibrils and the maximum fibril strains were evaluated as possible candidates for causing collagen damage. This evaluation was done by comparing the locations of maximum shear and tensile strains with the locations of initial collagen damage after mechanical overloading in bovine explants as found using antibodies directed against denatured type II collagen (Col2-3/4M). Collagen damage could be initiated by excessive shear strains along the collagen fibrils, and by excessive fibrils strains. The locations of collagen damage after mechanical overloading were highly dependent on the cartilage thickness, with thinner cartilage being more susceptible to damage than thicker samples. ß

Topographic Variations in Biomechanical and Biochemical Properties in the Ankle Joint: An In Vitro Bovine Study Evaluating Native and Engineered Cartilage

“…38 Excessive shear strain causes abundant collagen fibril strain that has been shown to correspond accurately with areas of collagen destruction leading to cartilage damage. 39 Our results showed that the tibial plafond exhibited 70% higher shear moduli in comparison with the talar dome. This study showed an important disparity in the ability of the tibial plafond and talus to withstand tensile, compressive, and shear forces, indicating the presence of a complex pathogenic mechanism responsible for cartilage degeneration.…”

Can Joint Contact Dynamics Be Restored by Anterior Cruciate Ligament Reconstruction?

“…These studies, however, have generally investigated only the path of tibial contact and have ignored the complex rolling and sliding components of the articular surface interaction. Given that articular cartilage is more susceptible to damage from shear than from compressive forces [38], the direction and magnitude of stress applied at the area of joint contact may be even more important than its location. The joint sliding distance, calculated from the femoral and tibial joint contact path lengths, reflects shear motion and is therefore related to shear stress.…”

Development of a Cartilage Shear-Damage Model to Investigate the Impact of Surface Injury on Chondrocytes and Extracellular Matrix Wear

“…16 Furthermore, shear stress has been documented with in vitro studies as a negative factor in cartilage failure as a response to injury and extracellular matrix wear. 17,18 Development of a superficial zone damage model through excessive shear would highlight the role of the superficial zone in the progression from healthy cartilage to PTOA. Superficial zone integrity is important for healthy cartilage function, as it provides resistance to shear forces due to the orientation of the collagen fibers.…”