Localization of uncemented hip stem loosening with a novel in-vivo sensor system based on vibration analysis

Abstract

The major reason for revision surgery of load bearing implants is aseptic loosening, especially with regard to total hip arthroplasty. Osseous anchorage of loosened implants needs to be measured exactly in order to ensure the indication for revision surgery and additionally to enable early detection of the loosening process. However, current diagnostic methods show unsatisfying results concerning sensitivity and specificity. Therefore, a new sensor system is being developed based on an acousto-mechanical approach, which can be used non-invasively and radiation-free to measure the stability of endoprosthesis fixation on the bone stock. This paper intends to show initial results of functional models, which are used to prove the measuring principle. © 2010 International Federation for Medical and Biological Engineering.