Lubrication Effects of Model Synovial Fluid on Hydrated Hydrogel Artificial Cartilage

摘要

Soft and hydrated articular cartilage which are covering surfaces of synovial joints is thought to be a key element of the sophisticated lubrication mechanism of natural synovial joints and indispensable to realize excellent low-friction and low-wear behavior in the human body. The application of highly hydrated hydrogel to the articulating surface of joint prostheses as artificial cartilage has been proposed to mimic the physical characteristics of natural joint surface and improve the lubrication mode of artificial joints from boundary to the full fluid film condition. However, there should be an additional lubrication mechanism by the interaction between biological molecules existing in the periprosthetic fluid and the articular surface material to keep the friction and wear always low under various joint movements. In this study, poly (vinyl alcohol) (PVA) hydrogel was selected as an artificial cartilage material and the lubrication ability of a model synovial fluid containing proteins and lipids was examined. Hip joint prosthesis models with PVA acetabular liner were prepared and the friction coefficient between a metal femoral head and the PVA liner was evaluated under the quasi-walking condition by using a custom-made hip joint simulator to access the lubrication effect.