0509 - a Small Punch Test Technique for Characterizing Pmma Used in Total Joint Replacement

Introduction. Failure of the bone cement in a total joint replacement can lead to implant loosening and ultimately necessitate device revision. Establishing and maintaining the integrity of the polymethylmethacrylate (PMMA) bone cement is thus important to the long-term performance of cemented joint replacements. In particular, the fracture toughness or work to failure of the cement may play an important role. In this study, we applied a novel testing technique, the small punch or miniaturized disc bend test, to explore its utility in characterizing the elastic and fracture properties of PMMA. Because of its miniature specimen size, the small punch test provides an advantage over bulk mechanical testing methods that require large specimens. The small punch test has been used to measure ductility and fracture resistance of metals and ceramics [1], as well as the mechanical behavior of ductile polymers, including UHMWPE [2]. In the current study, we examined the effect of temperature on the elastic, yield, and fracture behavior of a generic PMMA and of Simplex-P bone cement.