Investigation Into Piezoelectric Nanoparticle Dispersion in Polymethyl Methacrylate Bone Cement

Abstract Total knee arthroplasty (TKA) is one of the most common orthopedic surgeries performed in the United States. Though most cases of TKA are successful, some cases experience failure after the procedure. Smart implant technology seeks to aid the medical community in identifying failure that may require a revision surgery. Previous work in our research group explored sensing applications aimed at identifying failure in simulated total knee replacements (TKR) by bonding lead zirconate titanate (PZT) wafers to a tibial baseplate implanted in a simulated knee structure with artificial damage applied at the cement interface. Though this application demonstrated success with identifying failure in the simulated TKR system, there are improvements that can be made to the system. One improvement that must be made is the use of lead-free sensors in the biomedical system. Another possible improvement to the system is to relocate the piezoelectric sensor to the cement interface. A proposed method to implement these improvements is to develop a specialized sensing system with the specific application of joint replacements in mind, and more specifically, a sensing system in which the bone cement acts as the sensor. This study explores the idea of developing a piezoelectric nanocomposite in which bone cement is the primary material. The specialized piezoelectric nanocomposite is developed by adding barium titanate (BT) nanoparticles to the typical components of polymethyl methacrylate (PMMA) bone cement at various weight percentages of BT. The composite cement is then formed and cured into samples to be tested for compression strength. It must be shown that the suspension of barium titanate within the PMMA bone cement matrix does not compromise the mechanical properties of the cured cement. If the compression strength falls below 70 MPa, the cement will no longer meet the requirements of the ASTM standard for PMMA bone cement.