Transient and Residual Stresses and Displacements in Self-Curing Bone Cement—Part II: Thermoelastic Analysis of the Stem Fixation System

Abstract

In this second part of a two-part report, an idealized model of the stem fixation system is analyzed to determine the adverse effects of the thermal stresses and displacements of bone cement during its curing process. The Shaffer-Levitsky stress-rate strain-rate law for chemically hardening material has been used. The results show that if the cement is surrounded by cancellous bone, as opposed to cortical bone, then transient tensile circumferential stresses in the cement and similar radial stresses at the stem/cement interface are generated. The former may cause flaws and voids within the still curing cement, while the latter may cause gaps at the interface.