Jay, Gregory D., et al. The Association Between Friction and Wear in Diarthrodial Joints Lacking Lubricin. Arthritis & Rheumatism, 56(11):3662-9, 2007.
In contrast to man-made bearings, mammalian diarthrodial joints must endogenously produce friction-reducing agents. This study was undertaken to investigate whether friction is associated with wear. By studying the lubricating ability of synovial fluid (SF) samples from humans with genetic lubricin deficiency in vitro, and the coefficient of friction in the knee joints of normal and lubricin- mice ex vivo, it was found that friction is coupled with wear at the cartilage surface in vivo. This implies that acquired lubricin degradation occurring in inflammatory joint disease predisposes the cartilage to damage. Lastly, this study suggests that lubricin, or similar biomolecules, will have applications in man-made devices in which reducing friction is essential.