Abstract
Diamond-like carbon (DLC) coatings have the potential to reduce implant wear and thus to contribute to avoiding premature failure and increase service life of total knee replacements (TKAs). This two-part study addresses the development of such coatings for ultrahigh molecular weight polyethylene (UHMWPE) tibial inlays as well as cobalt–chromium–molybdenum (CoCr) and titanium (Ti64) alloy femoral components. While a detailed characterization of the tribological behavior is the subject of part II, part I focusses on the deposition of pure (a-C:H) and tungsten-doped hydrogen-containing amorphous carbon coatings (a-C:H:W) and the detailed characterization of their chemical, cytological, mechanical and adhesion behavior. The coatings are fabricated by physical vapor deposition (PVD) and display typical DLC morphology and composition, as verified by focused ion beam scanning electron microscopy and Raman spectroscopy. Their roughness is higher than that of the plain substrates. Initial screening with contact angle and surface tension as well as in vitro testing by indirect and direct application indicate favorable cytocompatibility. The DLC coatings feature excellent mechanical properties with a substantial enhancement of indentation hardness and elastic modulus ratios. The adhesion of the coatings as determined in modified scratch tests can be considered as sufficient for the use in TKAs.
Highlights
The failure of the natural human knee joint due to gonarthrosis or rheumatoid arthritis requires the implantation of a total knee arthroplasty (TKA) in order to restore joint functionality and provide patients with a pain-free and more mobile life [1]
The uncoated Ti64 pins featured a higher roughness than the CoCr pins and the ultrahigh molecular weight polyethylene (UHMWPE) disks, whereby the values for the last two were comparable
The roughness values were within the typical range for metallic TKA femoral components [78] and within the values specified by ISO 7207-2 [79] (Ra ≤ 0.1 μm)
Summary
The failure of the natural human knee joint due to gonarthrosis or rheumatoid arthritis requires the implantation of a total knee arthroplasty (TKA) in order to restore joint functionality and provide patients with a pain-free and more mobile life [1]. The application of biotribologically effective coatings on the articulating implant surfaces is a promising approach to increase wear resistance [13,14]. Due to the interaction with human tissue and synovial fluid with their large variety of cells and proteins, the coatings require sufficiently high biocompatibility [12] and adhesion. Repenning [15] summarized the aim of biotribologically effective coatings as a biological, chemical and physical modification of the interface between implant and tissue in order to enable a continuous improvement of functionality with respect to the biological environment
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
