Contribution to the study of fatigue cracked surfaces of bone cements "Biomaterial used in hip prosthesis"

Abstract

Acrylic bone cements have been widely used in orthopaedic surgery for the fixation of artificial joints. In total hip prosthesis, the fracture of poly methyl methacrylate (PMMA), through crack initiation propagation and fracture whether at an interface or within the bulk material is of serious concern since it leads to the implant failure. In the present study, cyclic fatigue fractured surfaces of six commercial bone cements, were investigated using two methods: roughness measurement and cleaved beads indicator (percentage of cleaved pre cured beads). The same surfaces were also inspected by Scanning Electron Microscope (SEM) for crack propagation patterns. Fatigue fractured surfaces of the cement tested were obtained using a methodology based on ASTM-E647-05. All cements tested showed three different morphologies which are in relation to the crack growth rate and cement type. The two methods are able to discriminate between the three zones and thus are quantitative inspections of the fractured surfaces (factorial ANOVA, p<0.0005).