An engineering report and related testimony given during the first DePuy ASR hip implant case to go to trial revealed that developers failed to adequately assess the device’s risks before they hit the market in 2003.
Johnson & Johnson’s orthopedic device unit, DePuy, completed the engineering report in November 2010, three months after it recalled its metal-on-metal ASR implants, the XL Acetabular and Hip Resurfacing systems. The assessment concluded that DePuy used improper engineering controls and standards in evaluating the risks the ASR hips might have in patients. The devices, which consist of a metal ball inserted into a metal cup, were then fast-tracked through the U.S. Food and Drug Administration 510(k) approval process and implanted in about 93,000 patients worldwide, including about 37,000 Americans.
During testimony given Thursday in California Superior Court in Los Angeles, DePuy Engineer Graham Isaac told the court that the ASR devices were only tested at one angle of implementation, so their performance in a broader spectrum of people was largely unknown. The ASR’s metal cup can be implanted at a number of angles depending on a patient’s build and the surgical techniques used.
This essentially meant that critical design flaws went undetected in DePuy’s labs. In the real world, variances from the single angle DePuy tested made friction between the metal ball and cup more likely to release metal particles into the patient’s tissue and blood.
Court documents unsealed before the trial started showed that DePuy executives knew in 2008 that the ASR hip implants were failing early at unusually high rates, but the company continued to make the devices for several more months before finally recalling them in August 2010. Newly released court documents also show that an internal DePuy review completed in 2011 found the devices failed within five years in about 40 percent of patients, yet DePuy officials withheld that information while disputing similar findings from external sources.
Internal DePuy records also document “that the product is more likely to experience contact between the head and rim” than metal implants made by other manufacturers, but company officials still failed to anticipate the wear this would have on the implant’s metal components and the potential harm it could do to patients.
Johnson & Johnson and DePuy face more than 10,000 lawsuits in the U.S. alleging injuries caused by the faulty metal implants. About 2,000 of those are consolidated in California Superior Court while the bulk of lawsuits have been combined for multidistrict litigation in U.S. District Court for the Northern District of Texas under Judge James Kinkeade.
Source: New York Times