| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 618786 | Wear | 2010 | 6 Pages |
Compliant layer technology, in which a soft polymer mimics the performance of natural cartilage, potentially represents a resolution to the wear and associated longevity coupled with conventional metal-on-plastic joints. In this two-part study, the friction and wear of compliant layer polyurethane (PU) tibial inserts articulating against metal femoral components were investigated as part of a preliminary in vitro screening.In Part I the friction and lubrication regimes were evaluated both experimentally using Stribeck analysis and theoretically using the theory of Hamrock and Dowson to investigate the joints ability to operate within a fluid film lubrication regime. Using aqueous carboxymethyl cellulose (CMC) fluids as the lubricant the joints were shown to operate with low friction and specifically, in some individual joints, with friction factors equivalent to ceramic-on-ceramic bearings as observed in hip bearings. Protein containing lubricants caused an increase in friction relative to the CMC solutions and it is proposed that this results from the shearing of interfacial protein layers adsorbed onto the articulating surfaces.Overall, the friction and lubrication results demonstrated the ability of compliant layer joints to operate with fluid film lubrication and consequential lower frictional torque during the walking cycle. In Part II of this study the wear performance of this articulation system will be investigated.
