Masafumi Morita

Development of an artificial joint with excellent fluid film lubrication performance: Part 2 Evaluation of lubricating film maintenance ability of the sliding surface@@@第２報 試作した摺動部コンポーネントの潤滑膜維持能の評価

As previously reported, we developed an ultra-low friction Total Hip Arthroplasty Components consists of a Ti-13Zr-13Nb femoral head with high sphericity and a UHMWPE acetabular socket. For these components, we evaluated the ability to maintain the lubricating film by using an artificial hip joint simulator and a detaching testing system of the femoral head from the acetabulum. As the results, the filloeing facts became clear. 1) The lubricating film was well maintained by radial clearance 13μm or less in the combination of PE acetabulum and metal head with the spericity of 8μm and 0.75μm, respectively. 2) If a good lubricating film is maintained in artificial joint sliding surface, the torque generated by the walking exercise fell to 1/100 of dry friction. Then, a good lubricating ability is kept at walking period 40rpm or more.