Potentially toxic metallic wear nanoparticles and trace metal ions release from metal-on-metal orthopedic implants in the human biological specimens: An Overview of in vivo and ex vivo clinical studies

The use of metallic biomaterials in the medical implant devices has become increasingly prevalent over the past few decades. Patients find themselves being exposed to metals in a variety of ways, ranging from external exposure to instruments such as medical devices to internal exposure via surgical devices being implanted in their bodies. In situ generation of metallic wear nanoparticles, corrosion products and in vivo trace metal ions release from metal and metallic alloys implanted into the body in orthopedic surgery is becoming a major cause for concern regarding the health and safety of patients. The chemical form, particulate vs. ionic, of the metal species in the bodily fluids and tissues is a key to the local nanotoxicity effects arising in the body. Potential health risks are associated with metallic wear debris in the form of nanoparticles in situ generation and the release of in vivo trace metal ions into human biological specimen's circulation. This overview explores how migration of metallic wear nanoparticles and ultratrace metal ions in the area of metal-on-metal orthopedic implants influences the surrounding tissues and bodily fluids, and what the toxicological consequences of this process may be. Specifically, the present article is more informative of indicative multilevel in situ/in vivo/ex vivo analytical/clinical methodologies which will be helpful in a way to plan, understand and lead the analytical innovations in the area of nano-analysis to improve patient outcomes.