The human hip joint plays a vital role in daily activities such as walking, standing, and running, contributing significantly to health-related quality of life. The joint's natural structure involves a ball- and-socket connection between the femur and pelvis, allowing for complex movements. Unfortunately, various factors, including trauma, wear, arthritis, and pathological conditions, can compromise the integrity of the hip joint, leading to conditions like osteoarthritis, developmental dysplasia, Paget's disease, and more.

Hip osteoarthritis, a prevalent cause of debilitating pain, often necessitates primary hip arthroplasty, a surgical procedure replacing the natural joint with an artificial implant. As the aging population undergoes increasing hip arthroplasties, monitoring the prosthetic's condition becomes crucial. Traditional inspection methods, such as x-ray and CT imaging, have limitations, including radiation exposure and can only capture a single frame.

The research performed explores the use of acoustic emissions (AE) as a non-invasive and continuous monitoring method for prosthetic hips. AE consists of “listening in” to the sound waves generated by the prosthesis during movement. Unlike other conventional imaging methods, AE allows for dynamic inspection of the prosthesis without subjecting the patient to ionising radiation. This research builds on previous work performed at the University of Canterbury by Dr. FitzPatrick, transferring the AE monitoring procedure from an overground gait on a stationary forceplate, to an instrumented treadmill to collect continuous, prolonged recordings with a steady state walking gait.

This study addresses key objectives, including successfully transitioning to an instrumented treadmill while still collecting the same quality of data to what was performed by Dr. FitzPatrick, reliably separating the combined ground reaction force during the double support stage of the walking gait into the left and right foot contributions, and the identification and mitigation of artefacts introduced by the instrumented treadmill. Additionally, modifications were made to the foot delineation methods that improved the accuracy of the delineation calculation, reducing the mean error.

In conclusion, this research advances the application of AE monitoring as a method for inspection of prosthetic hips by facilitating a larger data set to be collected allowing for future researchers to make broader conclusions on the features and trends observed from AE monitoring. These findings contribute to the ongoing efforts to enhance the reliability and longevity of hip prosthetics in an ageing population.