A correlation of radiographic "modes of failure" with clinical failure of cemented stem-type femoral components

Four modes of failure of cemented stem type femoral components are: pistoning within the medullary canal (mode I); medial migration of the proximal stem and lateral migration of the distal stem (mode II); medial lateral toggle of the distal stem tip (mode III); loss of proximal support with firm fixation of the distal end (mode IV). These radiographic failure patterns have been correlated with clinical findings at revision of 51 loose femoral components. The findings at revision correlated well with the radiographic findings indicating the accuracy of this nomenclature, which simplifies discussion of stem failures. Mode I was found to be the most common, and mode IV the most difficult to revise. Neither age, nor weight nor surgical approach influenced the failure mode. The overall results of revision were poor, with most hips rapidly assuming a IB type of appearance.