Development of operator independent bone cement vacuum mixing system for joint replacement surgery

Acrylic bone cement is weakened by its porosity, which promotes the formation of microcracks, which contribute to major crack propagation and ultimately failure of the cement mantle. Bone cement mixing techniques play a significant role in determining the quality of bone cement produced. A high degree of porosity is found to exist in cement that is inadequately mixed. Current commercial bone cement mixing systems allow for the preparation of the bone cement under the application of a vacuum in a closed, sealed chamber by means of a repeatable mixing action. These mixing systems are perceived to be repeatable and reliable by orthopaedic community. In this paper, the quality of bone cement mixed using an operator independent bone cement mixing system was compared with that of cement prepared using commercially available devices. The results of the investigation highlighted that cement prepared using the automated, repeatable mixing regime that is operator independent demonstrated consistently better physical and mechanical properties in comparison with cement mixed using proprietary cement mixing devices. Furthermore, Design of Experiments software established the optimal factors that influenced the physical and mechanical properties of PMMA bone cement.