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Updated: Jun 17, 2026
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Biotribological Testing and Analysis of Articular Cartilage Sliding against Metal for Implants
Published on: May 14, 2020
Tribological behavior of DLC-coated articulating joint implants
G Thorwarth1, C V Falub, U Müller
1Swiss Federal Institute for Materials Testing and Research (EMPA), Uberlandstrasse 129, CH-8600 Dübendorf, Switzerland. goetz.thorwarth@empa.ch
Acta Biomaterialia
|December 19, 2009
Summary
Diamond-like carbon (DLC) coatings show promise for joint replacements, outperforming metal-on-metal (MoM) implants in wear resistance. DLC coatings offer superior stability and adhesion in simulated physiological conditions.
Area of Science:
- Biomaterials Engineering
- Tribology
- Orthopedic Implants
Background:
- Diamond-like carbon (DLC) coatings are recognized for wear reduction in technical applications.
- Successful adaptation of DLC coatings for total joint replacement requires robust performance, stability, and adhesion in physiological environments.
- These critical aspects have not been consistently researched for DLC coatings in joint replacement contexts.
Purpose of the Study:
- To evaluate the long-term stability and performance of DLC implant coatings in simulated physiological conditions.
- To compare the wear characteristics of DLC-coated implants against traditional metal-on-metal (MoM) implant pairs.
- To investigate the influence of physiological media on tribological performance.
Main Methods:
- Utilized a simplified linear spinal simulator setup to test implant coating performance.
- Conducted wear testing on both DLC-coated and MoM implant pairs under cyclic loading.
- Monitored coating integrity and defect formation throughout the testing period.
- Investigated the tribological behavior in protein-containing and protein-free media.
Main Results:
- Metal-on-metal (MoM) pairs exhibited wear volumes over 20 times greater than DLC-coated implants after 7 million loading cycles, attributed to metal surface roughening.
- DLC-on-DLC tribopairs demonstrated low-friction conditions, whereas MoM pairs required protein-containing media to achieve similar results.
- Defect monitoring revealed catastrophic failure in DLC layers with weak interfaces susceptible to in vivo stress-corrosion-cracking mechanisms.
Conclusions:
- DLC coatings present a viable, wear-resistant alternative to MoM implants for joint replacement applications.
- Long-term stability and adhesion are critical factors for DLC coating success, particularly concerning in vivo stress-corrosion-cracking.
- Understanding the role of proteinaceous media is essential for optimizing tribological performance of implant surfaces.
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