Development and validation of an algorithm to determine the minimal factors needed for non-invasive measurement of the in vivo primary stability of cementless hip implants. (January 2023)

• Record Type: Journal Article
• Authors: Fonseca Ulloa, Carlos A.; Seeger, Anja; Hagedorn, Frederike S.; Harz, Torben; Fölsch, Christian; Ishaque, Bernd A.; Rickert, Markus; Jahnke, Alexander
• Is Part Of: Medical engineering & physics. Volume 111(2023)
• Publication Date: 2023-01
• Subjects: Biomechanics -- Endoprosthesis -- Primary and secondary stability -- Computational model -- Data acquisition -- Ultrasound; Biomedical engineering -- Periodicals; Biomedical Engineering -- Periodicals; Physics -- Periodicals; Génie biomédical -- Périodiques; Biomedical engineering; Electronic journals; Periodicals; 610.28
• DOI: 10.1016/j.medengphy.2022.103932
• Languages: English
• ISSNs: 1350-4533

Abstract

Highlights: New in vivo concept and algorithm to detect stem stability via micromotions. In vitro analyses don´t show biological processes after implantation. Validation and simulation for the non-invasive in vivo calculation of micromotions. This work creates a possible minimalistic solution for further in vivo diagnostics. Abstract: Aseptic loosening is a frequent cause for revision of endoprosthesis. X-ray examinations like Radio-Stereometry-Analysis (RSA) are among the most widely used in vivo methods for its detection. Nevertheless, this method is not used routinely because of bone marker and related radiation exposure. This work aims at creating a new in vivo concept to detect implant stability measuring micromotions without x-ray and to develop a corresponding algorithm. Based on the assumption of contactless measurement, the input parameters for the algorithm are the distances of each ultrasound sensor to the object (prosthesis and bone) and its position. First, the number of parameters necessary for a precise reconstruction and measurement of micromotions between objects had to be defined. Therefore, the algorithm has been tested with simulations of these parameters. Two experimental measurements, either using contact sensors or ultrasound, were used to prove the accuracy of the algorithm. Simulations indicate a high accuracy with three distances as initial parameters for each object. Contact measurements show precise representation of micromotion, and the contactless measurements show the possibility of detecting various materials with a high resolution. This work lays the foundations for non-invasive detection of micromotions between the implant-bone interface.