A new model for synovial joint lubrication.

A new approach to synovial joint lubrication is presented using Bingham fluid as lubricant between the approaching porous cartilagenous surfaces. It is presumed that the thickness of the core formed, due to thickly concentrated hyaluronic acid molecules, increases as the surfaces come closer. This is due to the withdrawal of the base fluid through the boosted lubrication mechanism, leading to the formation of lubricating gel. This gel ultimately acts as boundary lubricant which prevents cartilage-to-cartilage contacts very briefly during a gait cycle. For most of the gait cycle, fluid film lubrication persists, and this fluid supports greater loads which are due to the development of increased pressures as compared with viscous lubricants. Thus, normal joints possess an in-built mechanism to support greater loads, at the load-bearing joints, with less friction and wear.