A cytotoxicity and wear analysis of trapeziometacarpal total joint replacement implant consisting of DLC-coated Co-Cr-Mo alloy with the use of titanium gradient interlayer

Abstract

Diamond-like carbon (DLC) coatings exhibit excellent mechanical properties and improve the smoothness and the wear characteristic of the metallic component of total joint replacements. Although DLC is considered to be highly biocompatible, the effect of implant wear debris must be carefully analyzed. Simulated loading can help to mimic the wear of the implant in the human body over time. The purpose of the study presented here is to observe the wear of trapeziometacarpal (TMC) total joint arthroplasty implant consisting of DLC-coated Co-Cr-Mo alloy with the use of titanium gradient interlayer (Ti/Ti-C:H), and to analyze the potential cytotoxicity of the wear particles generated by simulated loading. No visible wear or delamination of the DLC coating was observed after 3 million cycles of increasing loading force up to 2.5 kN. Accordingly, no correlation was observed between increasing number of loading cycles (with increasing loading force) and decreasing proliferation of human osteoblast-like cells incubated in the wear suspension. We can therefore conclude that no cytotoxic wear debris was formed during the simulated loading of TMC total joint replacement implant composed of DLC-coated Co-Cr-Mo alloy with Ti/Ti-C:H gradient interlayer.