Tensor-resolved Raman spectroscopic analysis of wear-induced residual stress fields in long-term alumina hip-joint retrievals.

Abstract

Polarized Raman spectroscopy was applied to evaluate the full set of stress tensor components in the wear-induced residual stress fields on two long-term (>20 y) (monolithic) alumina (Al₂O₃) femoral head retrievals coupled to polyethylene liners. The tensor-resolved residual stress state stored onto the Al₂O₃ ceramic head surface was found to retain "memory" of the sliding conditions in vivo and of the wear-induced consumption of the polyethylene counterpart. The evolution of tensor-resolved residual stress motifs in the three-dimensional space was examined, and key features, including exceptionally high shear stresses in one case, were uncovered. The effect of such a body of concurrent complications and malfunctioning are neither easily reproducible by in vitro simulations nor obviously obtainable through merely computational approaches. It is demonstrated here that our latest developments of Raman spectroscopic algorithms could contribute to link the joint performance with the micromechanical features that occur in real in vivo situations.