Pharmaceutical

DePuy engineers knew of problems with metal hip implant but decided not to warn surgeons

DePuy ASR hip recall 435x369 DePuy engineers knew of problems with metal hip implant but decided not to warn surgeons An engineer with medical device maker DePuy Orthopaedics, a subsidiary of Johnson & Johnson, warned executives in 2008 that its ASR metal-on-metal hip replacement system is susceptible to releasing extreme metal ions into the bloodstream of patients who had the devices implanted in their bodies, and said that the company needed “to discuss this at the earliest possible opportunity as I believe it means that we need to start any ASR upgrade sooner than our previous plans had suggested.”

The DePuy engineer who warned colleagues was Graham Isaac and, despite a memo documenting his concerns about the ASR, Isaac said during a lawsuit currently underway in California that the possibility of the hip implants poisoning the blood of patients was not serious enough to warrant warning surgeons.

Now, however, DePuy and Johnson & Johnson are facing more than 10,000 lawsuits related to the ASR artificial hip. The devices were launched in the United States in 2005 but were recalled five years later after reports of unexpectedly high number of premature failures. The worldwide recall affects an estimated 93,000 people, 37,000 of whom live in the United States.

It was soon discovered that the early failures were likely a result of metal debris from the all-metal implant falling into the joint space, which can cause tissue death. Metal ions were also seeping into the bloodstreams of some patients, leading to a type of blood poisoning known as metallosis. The condition carries with it a host of possible health concerns, including cancer.

Yet, the company didn’t think it necessary to warn surgeons or patients of the possible risks associated with the devices. Internal emails show that Johnson & Johnson and DePuy were receiving complaints about the devices as early as 2005 and 2006. A year later, a DePuy engineer warned that metal ion seepage in patients could likely appear in journals and hurt the company’s image. Thus, “We will ultimately need a cup redesign but the short term action is manage perceptions.”

DePuy never redesigned the ASR hip implant. Instead, the company chose to phase out sales in November 2009, a year before the devices were recalled. The company’s president, Andrew Ekdahl, in video testimony shown to jurors late last month, refused to admit the devices are unsafe.

Source: The Economist