A Polymethyl Methacrylate Bone Cement With Reduced Stress Concentration

Polymethyl methacrylate (PMMA) bone cement is the earliest and most widely used in clinical applications. However, PMMA bone cement has high hardness and high modulus, which leads to secondary fracture of adjacent vertebrae. In this study, a PMMA/polylactic acid (PLA)/carbon nanotube (CNT) compound bone cement with decreased compression modulus is developed for overcoming the limitation of PMMA commercial bone cement (CBC). Compared with CBC, the compression modulus of composite PMMA/PLA/CNT bone cements is reduced from 893.34 MPa (CBC) to 487.25 MPa (54.54% of the CBC), which is beneficial for reducing stress concentration at the bone implantation site. The cytotoxicity studies also indicate that the prepared composite cements are nontoxic and harmless, which has the necessary condition for orthopedic clinical applications.