Orthopaedic bone cement is used throughout the world to secure hip, knee and other metallic prostheses in an appropriate medical position. Also, bone cement can be used to replace and/or repair damaged bone, such as a bone void filling and spinal column with degenerative intervertebral discs by permanently stabilising adjacent vertabrae by fusion. Cement may be applied by hand or may be put into a syringe and applied separately. However, this simple mixing has two major drawbacks. Firstly, free methylmethacrylate fumes are emitted from the mixture. Secondly, a very high mixing efficiency is required to produce a homogenous cement material. The specification discloses a device for mixing bone cement material, the device comprising a mixing body having a chamber, and wherein the mixing body has an open end； a lid arranged to be fitted to the open end； means for mixing bone cement material in the chamber, the means for mixing comprising a rod extending through the lid and into the chamber, wherein the rod has a frangible portion； said lid comprising a cap moveable to a first position covering the frangible portion of the rod, and to a second position revealing the frangible portion.
