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The EMBS Chapter of the IEEE Ottawa Section was recognized as the Best Ottawa Chapter in 2008, 2010, and 2014 and received the Outstanding Chapter Award from IEEE EMBS in 2011!

Total Hip Replacements: Failure, Retrieval and In Vitro Assessment of Strength, Durability and Distraction

Dr. Michel Nganbe

Associate Professor, Department of Mechanical Engineering, University of Ottawa

October 17, 2013 15:00 - 16:00

River Building, room 3228, Carleton University

co-sponsered by Life Members Affinity group

abstract

Recent premature failures of metal total hip replacements (THRs) have raised concerns about their load bearing capacity, safety, reliability and survival rates. THR failures lead to painful and costly revision surgeries projected to exceed 3.5 billion US dollars per year in 2015 alone for metal-on-metal implants in the United States. The absence of interfaces in non-modular implants eliminates interface corrosion, galling and particle release. However, revision surgeries are more costly as the entire THR needs to be replaced. In contrast, modular implants allow patient specific adjustments and easier revision as components can be replaced separately as required. However, they pose serious challenges with respect to potential toxicity and other adverse body reactions caused by metal particle release from component junctions. Our results show that (1) fretting, galling and wear particle release are accelerated during the initial implantation phase as the components settle; (2) CoCrMo necks exhibit 38% higher load bearing capacity and longer fatigue life compared to Ti6Al4V necks; (3) for younger, more active patients as well as for patients with high body mass index, the implant can over time reach its fatigue limit leading to failure and the need for revision surgery. This illustrates the need for continuous patient monitoring and improved testing standards.

biography

Dr. Nganbe is Associate Professor at the Department of Mechanical Engineering, University of Ottawa, which he joined in 2006 following 5 years in industry. He is active in teaching and research in Materials and Manufacturing. His research interests are metals and metal based alloys and composites for functional, biological and structural applications. He received his Ph.D. in 2002 from the Dresden University of Technology in Germany. During his doctoral research he worked with the Leibniz Institute for Solid State and Materials Research on precipitation- and dispersion-strengthened superalloys. He worked on automotive components development as Test Engineer in Germany from 2001 to 2004, on metal foams development as Research and Development Manager in Montreal and on nanostructured coatings as NSERC Industrial Research Fellow in Calgary from 2005 to 2006.

Last updated September 19, 2013

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