The human patellar tendon is mechanically homogenous at its mid-substance.

The human patellar tendon contains distinct fascicle bundles across its mediolateral and anteroposterior regions. Studies have suggested region-specific behaviour during in vivo actions, but it is unclear whether such regional differences result from localized variation in composition and mechanical properties within the tendon itself. Furthermore, the viscoelastic properties of any region of the human patellar tendon have not been well described previously.

Comparison of site-specific tensile, compressive, and friction properties of human tibiofemoral joint cartilage and their relationship to degeneration.

Site-specific differences in the compressive properties of tibiofemoral joint articular cartilage are well-documented, while exploration of tensile and frictional properties in humans remains limited. Thus, this study aimed to characterize and compare the tensile, compressive and frictional properties of articular cartilage across different sites of the tibiofemoral joint, and to establish relationships between these properties and cartilage degeneration. We cut human tibiofemoral joint (N = 5) cartilage surfaces into tensile testing samples (n = 155) and osteochondral plugs (n = 40) to determine the tensile, friction and compressive properties, as well as OARSI grades.

Loss of collagen content is localized near cartilage lesions on the day of injurious loading and intensified on day 12.

Joint injury can lead to articular cartilage damage, excessive inflammation, and post-traumatic osteoarthritis (PTOA). Collagen is an essential component for cartilage function, yet current literature has limited understanding of how biochemical and biomechanical factors contribute to collagen loss in injured cartilage. Our aim was to investigate spatially dependent changes in collagen content and collagen integrity of injured cartilage, with an explant model of early-stage PTOA.