Biotribology behavior and fluid load support of PVA/HA composite hydrogel as artificial cartilage

The human body joint motion is very complicated, which mainly includes sliding, swing, rotation. Therefore, cartilage covering the joint surface bears the repeated friction which is caused by the different movements during the whole life. So sliding, swing and torsion friction behavior of hydrogels need to be researched as synthetic articular cartilage. In this paper, PVA/HA composite hydrogel is cross-linked on the UHMWPE surface through chemical grafting and freezing-thawing method. Biotribology behavior and fluid load support are researched. The results show that swing and torsion friction coefficients are negligibly small, while sliding friction coefficient is largest. There is a negative linear relationship between fluid load support and friction coefficient. Fluid load supports are relative high under swing and torsion friction, so the swing and torsion friction coefficients are relative low. Hydrogel can be replenished by re-swelling to sustain the fluid pressurization during friction under lubrication condition. Both fluid load support and biphasic lubrication due to its porous structure with large amount of water contribute to the low friction coefficient.