ARTHRITIS AND THE INTERACTING MECHANISMS OF SYNOVIAL JOINT LUBRICATION .1. OPERATING-CONDITIONS AND THE ENVIRONMENT

The lubrication mechanisms in synovial joints and how their combined e ffect provides low friction and wear under widely varying conditions a re reviewed in this work. Physical factors initiating the failure of s ynovial joint lubrication and the onset of arthritis are also discusse d. It is postulated that synovial joint lubrication is provided both s eparately and interactively by the cartilage and the synovial fluid. T he living environment of a synovial joint can both favour and impede s ynovial lubrication. Synovial lubrication mechanisms may respond to ch anges in loading as well as to ageing. Self-destructive changes in lub rication can occur and promote arthritis. The effect of joint inflamma tion on lubrication mechanisms remains largely unknown. The role of tr ansient frictional temperatures in synovial fluid between opposing car tilage surfaces remains largely uninvestigated. In Part I of this work the issues relating to the intricate nature of synovial joints, opera ting conditions and living environment are addressed.