Developing a New Generation of Bone Cements With Nanotechnology

Around 500,000 people have total joint (including hip and knee) replacement surgeries each year. However, current joint implants last only 10 to 15 years before failing. Undoubtly because of this, many patients have to go through a revision surgery due to the failure of bone implants. The main reason for implant failure is aseptic loosening of the implant from juxtaposed bone. In this light, polymethyl methacrylate (PMMA) has been used widely in orthopedics to improve the bonding between the implant and bone. In total hip replacement procedures, PMMA cement is located at the bone-implant interface and plays an important role in inhibiting the aseptic loosening processes. PMMA cement is associated with several drawbacks that limit its efficacy (such as strong exothermic reactions, weak radiopacity and poor fatigue strength; all leading to insufficient bonding to bone). With an expectation of increased revision surgeries and patients receiving orthopedic implants in the coming years, the emphasis of joint replacement research needs to be focused on improving the mechanical and biocompatibility properties of bone cements. As nanotechnology has been extensively used to improve mechanical and surface properties of implant materials, it certainly provides a unique opportunity to modify the material properties of currently used bone cements in a more precise manner. This article reviews nanotechnology-based advancements made to PMMA cement and bioactive cements (Bis-GMA cement and calcium phosphate cement (CPC)). A discussion of accomplishments, potentials and challenges for the application of nanotechnology in bone cements then follows.