Key UC Contact
What We Did
Starting from 2010, Prof Geoff Rodgers has worked with UC PhD student, and now Postdoctoral Fellow, Dr Anthony FitzPatrick, as well as collaborators at the University of Otago Christchurch School of Medicine to create an acoustic emission monitoring system that monitors the sound vibrations transmitted from a patient’s hip replacement implants. By listening to the ultrasonic vibrations of the implant, it is possible to relate them to the condition of the implant, to help orthopaedic surgeons predict impending failures and manage revision surgery. It is entirely non-invasive and can detect issues when a patient is moving and the implant is loaded. This compares favourably to existing, largely static, diagnostic methods such as x-rays, bone scans, and Magnetic Resonance Imaging (MRI), which require specialised, non-portable and expensive equipment, and experienced operators. “We are combining acoustic emission monitoring with motion tracking and biomechanical modelling”, says Dr Rodgers. “We believe this multiple sensor approach and associated modelling will lead to new insights into hip implant mechanics and could improve patient care, by providing an additional diagnostic method to orthopaedic surgeons.” This research entitled Unique Acoustic Signatures to Diagnose Impending DOOM (Dysfunction of Osteo-Mechanics), has been undertaken thanks to funding from MBIE, the MedTech CoRE, and a Marsden Grant administered by the Royal Society Te Apārangi.
Who Was Involved
UC’s Dr Anthony FitzPatrick and Prof Geoff Rodgers, along with collaborators from the University of Otago Christchurch Department of Orthopaedic Surgery, including Professor Gary Hooper and Professor Tim Woodfield.
Why It Matters
Joint replacement surgery has the ability to significantly improve the lifestyle of patients who have disabling arthritis. The requirement for this surgery is increasing rapidly with predictions of a 300% increase in knee replacement by 2030. Early detection of wear and tear can lead to proactive intervention, reducing the severity of surgery and providing improved patient outcomes.
Learn More
- Roffe L., FitzPatrick AJ., Rodgers GW., Woodfield TBF. and Hooper GJ. (2017) Squeaking in ceramic-on-ceramic hips: No evidence of contribution from the trunnion morse taper. Journal of Orthopaedic Research 35(8): 1793-1798. http://dx.doi.org/10.1002/jor.23458.
- FitzPatrick, A. J., Rodgers, G. W., Woodfield, T. B., & Hooper, G. J. (2017). Cepstrum Analysis for Determining the Fundamental Frequency of Total Hip Replacement Acoustic Emissions. IFAC-PapersOnLine, 50(1), 9932-9937. https://doi.org/10.1016/j.ifacol.2017.08.1642
- FitzPatrick, A. J., Rodgers, G. W., Hooper, G. J., & Woodfield, T. B. (2017). Development and validation of an acoustic emission device to measure wear in total hip replacements in-vitro and in-vivo. Biomedical Signal Processing and Control, 33, 281-288. https://doi.org/10.1016/j.bspc.2016.12.011
