Quantitative Ultrasound for Hip Joint Prostheses Osteointegration Monitoring

Abstract

Background, Motivation and Objective

Hip joint prostheses (HJP) are increasingly common with an aging population. The most frequent complication is aseptic loosening, linked to bone resorption and a growing soft tissue gap between bone and implant. However, integration monitoring and loosening diagnosis still rely on expensive, static X-ray imaging. Ultrasound, despite cheaper, dynamic, and radiation-free, is not yet viable due to its limits in resolving tissue beyond the bone.

This work presents how a novel quantitative ultrasound (QUS) data processing approach could improve HJP monitoring by quantitatively assessing osteointegration. While the basic concept was already tested on artificial models, we now show first clinical results for ultrasonic thickness measurements of the bone-implant gap at hip implant patients compared to X-ray imaging.

 

Statement of Contribution/Methods

Our approach is based on an analysis of raw (RF) beamformed ultrasonic data. A scan line perpendicular to the bone surface is extracted and a certain signal range following the dominant bone reflection is transformed to the frequency domain using a Fast Fourier Transform (FFT) (a). The gap thickness, indicating local osteointegration quality and potential loosening signs, is then determined by evaluating the frequency spacing of minima in the amplitude spectrum.

To demonstrate the potential of our QUS method, we analyzed ultrasonic scans from six HJP patients at one fixed position each (sagittal and transversal) using a handheld scanner (C3 HD3, Clarius, Canada) and compared the measured gap thicknesses with x-ray images.

 

Results/Discussion

(b) shows the gap thicknesses determined using our QUS method in comparison with the visual assessment of corresponding X-ray images. Despite the small sample size and some simplifying assumptions used for this first feasibility test, the clear trend highlights the approach’s potential for assessing local implant integration. The cases where no gap could be seen in the x-ray image illustrate its potential for gap detection beyond X-ray resolution limits.

Besides gap thickness, our QUS approach could also reveal elasticity changes in the soft-tissue gap, potentially indicating critical biofilm formation. Further steps also include extending our method to an automated thickness detection during dynamic scanning and integrating results into B-mode images, e. g., using color coding.

Mehr zum Titel

Titel	Quantitative Ultrasound for Hip Joint Prostheses Osteointegration Monitoring
Medien	Talk, 2025 IEEE International Ultrasonics Symposium (IUS), Utrecht, 2025
Verfasser	M.Eng. Jan Lützelberger
Veröffentlichungsdatum	17.09.2025
Projekttitel	UltraHip
Zitation	Lützelberger, Jan (2025): Quantitative Ultrasound for Hip Joint Prostheses Osteointegration Monitoring. Talk, 2025 IEEE International Ultrasonics Symposium (IUS), Utrecht, 2025.