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February 7, 2013

DePuy ASR Hip Implant Recall

DePuy Hip Implant.jpg
Over 10,000 lawsuits have been filed against the company Johnson & Johnson for their distribution of the DePuy ASR hip implant, since a recall was issued in August 2010. The DePuy ASR hip implant has a metal on metal design, which means that a metal head rotates within a metal cup. This design causes metal debris, caused from the metal parts rubbing against each other, to be released into the surrounding tissue and cause medical problems. The failure occurs within five years of replacement.

When the recall was first issued, Johnson & Johnson stated that the failure rate was only about 13%, but after documents were released as part of the litigation, it was estimated that the failure rate of the DePuy ASR hip implant is as high as 37%. This means that one out of every eight DePuy ASR hip implants were failing within five years of replacement surgery.

There is currently a case going on in California against Johnson & Johnson for the marketing, manufacturing and sale of the defective DePuy ASR hip implants. It is being said that the company failed to properly warn the public, as well as healthcare professionals, about the risk of loosening and other complications that may develop shortly after hip replacement surgery.

In testimony in the current case being heard in California, a DePuy engineer testified that Johnson & Johnson only tested one angle of implantation and that the company failed to use the right engineering controls when trying to assess potential problems. The engineer further stated that the testing conducted failed to predict how much wear the hip implants would experience and how much they could loosen.

The FDA released a new guidance for metal on metal hip replacements in January of this year. Doctors were advised that metal on metal hip replacement systems should only be used if other artificial hip implants were not appropriate for the patient, and called on all manufacturers to prove that their implants are safe enough to stay on the market. Also, future metal on metal hip designs will have to undergo extensive human clinical trials before being made available for sale to the public.

April 7, 2010

Human Factors Experts Testimony in Product Liability Cases Is On the Rise

The Food and Drug Administration (FDA) has regulations, guidance documents and industry standards in relation to the use of human factors experts, which allow for more effective cross-examination and a strong defense in Product Liability Cases. With these regulations, human factors not only base their expert opinion on speculation, but also on facts.

You may be asking yourself, what are Human Factors, well it is the study of the relationships between humans, the tools they use, and the environment in which they live and work.

It is with these tools that human factors experts are allowed to testify in cases to provide opinions regarding the adequacy and efficacy of warnings and/or the impact of human factors in the design of products. The Expert must be able to identify a reliable scientific basis for his/her opinion to be used as testimony. It is the goal of the human factors professional to eliminate user error through proper product design and labeling.

Medical devices that are designed by the FDA are designed with the human factor principles in mind. According to the FDA manufacturers must use the following three device classes/guidelines when manufacturing a device for human use:

- The Manufacturer must consider human factors in the development of the device. Such things as what the user sees, feels and hears;
- The Manufacturer must test all devices for the potential in error use by the user;
- The Manufacturer, when conducting risk analysis of the device, must consider user error.

These three device classes must all be subject to good manufacturing practices (GMPs) and these can be found in its Quality System Regulations. It is imperative that the medical device withstand the actions and inactions of its intended user, in order to design an error-tolerant medical device. It is important that the developer consider the characteristics of the worst case user. It is this underlying philosophy that human factor experts are used for.

These Human Factors Principles are also embraced by the Association for the Advancement of Medical Instruments (AAMI), the International Electrotechnical Commission (IEC) and the International Organization for Standardization (ISO)