Bone cement is used as load-distributing filler between the prosthesis and the bone, as well as a method to anchor prosthesis in orthopedic implants. One of the disadvantages of using polymethylmethacrylate (PMMA) as bone cement is shrinkage of the cement during polymerization. Shrinkage of the cement during polymerization may lose the good load transfer through the interface between the bone and bone cement, and is a source of prosthetic loosening. A crosslinked poly(methy methacrylate-acrylic acid-allylmethacrylate) was applied to bone cement, because it was found that this copolymer exhibits the ability to absorb body fluids and swell in a controlled manner to compensate shrinkage of the cement during polymerization. In this study, the crosslinked poly(methy methacrylate-acrylic acid-allylmethacrylate) modified bone cement was prepared and characterized using tensile analysis and dynamic mechanical analysis. The results show that the modified bone cement is able to enhance the mechanical properties of bone cement. From dynamic mechanical analysis, the transition temperature and the tan 5 value of the cement may be affected by prepolymerized crosslinked poly(methylmethacrylate-acrylic acid-allylmethacrylate) powder. From the observation of the fracture surfaces of the cements, the modified bone cement may improve fracture toughness. (c) 2006 Wiley Periodicals, Inc.