Understanding the origins of Implant derived debris

It has been proposed that taper corrosion in metal-on-polyethylene total hip arthroplasty (THA) has the potential to cause adverse local tissue reactions. This can go on to cause severe complications and ultimately failure of the implant through immune response. Several studies in the literature highlight that this is likely to be related to increased metal debris generated from the modular taper junction. ASTM and ISO standards are still primitive when it comes to assessing the complex degradation mechanisms of THA and often rely solely on simple gravimetric mass loss. Recent work at Leeds has pioneered in-situ measurement of these processes along with complex whole system THA simulation. Gauging performance is therefore difficult and no standard methodology exists to determine the size and properties of particles and/or metal ions and corrosion products released from aforementioned interfaces. External regulatory drivers from the FDA are now demanding manufacturers have a sound understanding of any potential source of debris or degradation products likely to arise from devices in vivo. This project therefore aims to characterise the size, morphology and chemical composition of wear debris and degradation products released from interfaces commonly found in THA components. For the first time state-of-the-art whole hip simulation will be used as opposed to studying the interfaces in isolation with the ability to systematically de-couple interfaces. This will increase the knowledge in the orthopaedic community about the size and properties of particles released specifically from taper junctions and how they compare to other articulating surfaces. Work will include in situ measurements of degradation as well as rigorous pre- and post-test analysis. Existing test methods and standards will be compared and used to inform novel testing methods and conditions.