Assessing the viability of additive manufacturing for partial replacement technologies - PrintPartialImplant

Additive Manufacturing is a technique that allows the direct fabrication of functional parts with complex shapes from digital models and is particularly suitable for low production volumes and for complex components requiring high machining costs. These characteristics make additive manufacturing particularly promising as a technique for manufacturing partial replacement technology tailor made to individual patients. Partial replacements are currently gaining relevance as less aggressive alternative to total joint replacements in patients with osteoarthritis. This surgery is smaller and allow faster rehabilitation, even though the rates of failures are significantly higher than after total joint replacement. This is related to the progressive degeneration of the preserved area of joint surface that remains after partial replacement or loosening or biomechanic insufficiency of the implant. However, there is little research done on the tribological behaviour of articular cartilage and adjacent metal implants with respect to the influence of wear on the remaining cartilage or inflammatory reaction of the existing cartilage on the residing implant or other phenomena that might occur like corrosion. This project will investigate the interfacial interaction of additive manufactured partial implants during sliding contact against cartilage with focus on the role of biotribocorrision, i.e. combined effect of mechanical wear and corrosion. Their finer microstructure compared to conventional implants together with their lower porosity make additive manufactured components specially promising for biotribocorrosion applications. Special emphasis will be given to the presence of proteins and adsorbed protein layers on the implant surface and the role of inflammatory agents mimicking unhealthy conditions. Complementary investigations will be performed by adding metal ions to the medium with the aim of determining critical concentrations for chondrocyte viability. The results will serve as basis for evaluating the potential of additive manufacturing on partial replacement technology in order to decrease the rate of failure of partial joint replacements and spread them to a wider range of patients.