Effect of Enzymatic Degeneration on the Frictonal Property of Articular Cartilage

Articular cartilage is consisted of the chondrocyte, collagen fibers and proteoglycan, and interstitial fluid. Basalo et al reported that the coefficient of friction of bovine articular cartilage on a glass surface measured in unconfined compression fashion was increased by the degeneration of proteoglycan ^[1]. In their friction test, it was difficult to test a small cartilage sample having undulation while the loaded area in cartilage specimen was almost unchanged during friction. For the assessment of frictional properties of enzymatically degenerated cartilage in more physiological condition, we developed a friction tester that allows for performing friction tests of articular cartilage surface against a spherical indenter. With the tester, the loaded area in cartilage specimen translated along with frictional motion while the compressive stress exceeded more than 1 MPa. In the present study, the effect of enzymatic degeneration of proteoglycan and collagen fiber on property of articular cartilage using the friction tester.