Toward long-live ceramic on ceramic hip joints: In vitro investigation of squeaking of coated hip joint with layer-by-layer reinforced PVA coatings

This study attempts to find a promising solution for the squeaking of ceramic on ceramic (COC) bearing surfaces by introducing reinforced poly(vinylalcohol) (PVA) layer-by-layer coatings on the bearing surface of Stryker Trident femoral head. A customized hip simulator was established to provide a realistic simulation of the normal gait (flexion–extension) of the hip joint, and to examine squeaking for coated and uncoated femoral heads. Different characterization techniques were employed to study the coatings’ structure. The PVA macromolecules were successfully cross-linked via epichlorohydrin agent, and chemically bonded onto the surface, forming a superior reinforced PVA coating on the femoral head’s surface. These coatings play a dominant role in increasing the pre-squeaking age of the hip joint due to reduction in hard-on-hard contact and femoral head liner clearance with their good viscoelastic properties. Which cause, damping friction-induced vibrations. This improvement resembles novel-type, long-life, and stable hip joint biomaterials with distinguished and promising pre-squeaking age.