The Trial Lawyer Fall 2017 - Page 38

This is why explant testing is so important. Widely used in various phases of the product life cycle, failure modes and effects analysis (FMEA) helps identify potential failures based on experience with similar products, or based on common physics of failure logic. Effects analysis relates to the consequences of failures on different system levels. For example, to what degree might friction between the femoral head and acetabular component (resulting from failure in the plastic liner) shorten the life expectancy of an artificial hip? Explant testing often employs a process known as positive material identification (PMI). International standards organizations ASTM and ISO have endorsed PMI, and its results are admissible in court. In fact, were I to judge such cases, I would make sure that test labs were accredited to ISO 17025, as this is the highest attainable testing accreditation. PMI helps to validate the s tructural integrity of any given implant and consists of the following: • Full wet chemistry (with gasses), to confirm the alloy was made to the 36 x The Trial Lawyer specification • Fractography to characterize the fracture surface and/or wear surface • Grain evaluation (up to 600X), to determine the material was thermally processed properly • Micro-hardness, edge to core • In some instances, mini tensile bars are fabricated to determine tensile strength, yield strength, % elongation and % yield Findings from explant testing allow manufacturers to issue recalls, make design modifications, and apply lessons learned to next-generation products. The information is also valuable to all parties involved in insurance claims and litigation. Understanding What’s At Stake There’s no denying that medical implant/ devices are improving the quality of life for countless individuals. However, when they fail (for whatever reason) the consequences can be catastrophic. In order to best represent and advise clients, lawyers on both side of the aisle must have a thorough understanding supported by scientific proof of the exact cause(s) for failure. Testing in general and failure analysis in particular can uncover even the most subtle design, manufacturing, or installation flaws. As a professional test engineer and expert witness I’ve personally seen a micro-inch deviation in implant product tolerance win cases. In a world where information is king, failure analysis provides undisputable scientific proof. Armed with this information trial lawyers across the country can act in the best interest of their clients, get to the root cause(s), and hold responsible parties accountable. John McCloy is founder and president of Engineered Assurance, LLC (www. and the former owner of Accutek Testing Laboratory, a mechanical and metallurgical testing laboratory for clients from the medical, aerospace, and defense industries. Mr. McCloy remains an active member of the American Society of Testing Materials (ASTM), the American Society of Metals (ASM) and the American Welding Society (AWS).