Polymethyl methacrylate bone cement composition comprises polymethyl methacrylate, X-ray opaque, methyl methacrylate and alkyl methacrylates. An initiator system, ferromagnetic, superparamagnetic particles having a particle size up to 500mu m and a biodegradable or biocompatible crystalline substance with a melting point of 42-80[deg] C is also included. A cytotoxic agent is additionally included in the bone cement composition.