Multifunctional Ceramic Thin Films for High-Performance Orthopaedic Implants

M. Bianchi, N. Lopomo, M. Boi, M.C. Maltarello, F. Liscio, M. Marcacci, A. Russo
Istituto Ortopedico Rizzoli, IT

Keywords: thin films, orthopedics, load-bearing, osseointegration

Summary:

We describe here the deposition via a novel sputter-based electron deposition technique of functional ceramic thin films on the surface of the two main components of an orthopaedic implant: the load-bearing component and the segment of the implant interested by the osseointegration process. The final aim of our research is the improvement of the long-term mechanical and osseointegration performances of said components, respectively. Concerning the load-bearing component, we deposited hard ceramic zirconia (YSZ) and zirconia-toughened alumina (ZTA) films directly on the surface of the UHMWPE inlet, obtaining a strong reduction of plastic deformation and creep of the UHMWPE inlet as well as very low wear rates. Concerning the segment of the implant involved in the osseointegration process, it is known that both the composition and the phase structure of commercial hydroxyapatite (HA) deposited on the surface of the metallic implant to enhance its ossoeintegration properties, are far away from that of bone apatite. Further, mechanical properties, adhesion and homogeneity of HA coatings should be greatly improved. Our research envisages the deposition apatite coatings resembling bone apatite, in terms of chemical composition and micro-structure by using as target material the most similar to bone material available: bone itself.