title: Nondestructive evaluation of bone cement and bone cement/metal interface failure.
abstract: To quantify the failure mechanisms related to the loosening of cemented hip joint replacements, novel techniques, capable of monitoring, nondestructively, the initiation and progression of failure during in vitro fatigue tests, were employed. Fatigue testing of model cement and cement-stem test pieces was monitored using acoustic emission (AE) sensors. Once damage was detected, an ultrasonic imaging system was used to obtain an image of the damage site and to measure the stiffness of the affected region. This method of examination provided a detailed insight into the internal crack propagation and delamination patterns. Initial work was conducted on bulk cement specimens subjected to bending and tension. The second stage of the work examined a model stem-cement interface under tensile opening loading conditions. A novel ultrasonic technique was used to measure the bond quality at the cement-metal interface. Progressive delamination was identified over time, and the AE technique was able to identify critical areas of delamination before they could be identified conclusively by ultrasonic imaging. The work has demonstrated the potential of the AE technique as a tool for the preclinical assessment of total hip replacements.
authors.affiliation: Bioengineering Sciences Research Group, School of Engineering Sciences, University of Southampton, Southampton, SO17 1BJ, UK. doctor@soton.ac.uk
authors.forename: M
authors.initials: M
authors.lastname: Browne
authors.forename: J R T
authors.initials: JR
authors.lastname: Jeffers
authors.forename: N
authors.initials: N
authors.lastname: Saffari
mesh_terms: D001843:Bone Cements / Q000737:chemistry*; D019544:Equipment Failure Analysis; D008422:Materials Testing; D008670:Metals / Q000737:chemistry*; D019904:Polymethyl Methacrylate; D011138:Polytetrafluoroethylene; D011475:Prosthesis Failure; D013718:Tensile Strength; D014159:Transducers; D014465:Ultrasonics
chemical_list: D001843:Bone Cements; D008670:Metals; D011138:Polytetrafluoroethylene; D019904:Polymethyl Methacrylate