In August 2010, DePuy Orthopaedics (a division of Johnson & Johnson) recalled two hip-replacement units:  the ASR XL Acetabular System and the ASR Hip Resurfacing System. According to DePuy, more than 93,000 patients worldwide had one of these two products implanted, many of whom have since decided to file a DePuy ASR lawsuit.

DePuy ASR Lawsuit – Defective Design

Individuals pursuing a DePuy ASR hip lawsuit are alleging, among other things, that the hip implants were defectively designed.  To understand just what went wrong, it is necessary to know the basics of how a hip works.  The hip has two major components that fit together like a ball in a socket. The socket part of the hip is called the acetabulum.  The rounded head of the femur (leg) bone is the ball that fits into the curved acetabulum. When either of these components is damaged or deteriorates, individuals may experience severe pain that makes it difficult to walk or even stand.  Many patients who reach this stage opt for partial or total hip replacement surgery.

Approximately, 250,000 people in the United States receive hip replacements each year, with almost one-third receiving metal-on-metal hip implants (such as the DePuy ASR hip devices). Metal-on-metal hip implants are hip implants made of a metal head and a metal acetabulum or a metal liner sitting inside the acetabulum.  Some orthopedic doctors believe that the DePuy ASR replacements contained a design flaw that made them difficult to implant. Specifically, the ASR metal cup (the device that replaces the acetabulum) is shallower than comparable devices, making it difficult to place the implant properly inside the recipient’s body.  Some experts have speculated that the metal fragments deposited by an ASR hip replacement inhibit bone growth.  This results in a failure of the ASR implant to properly adhere to a patient’s body.

Dangerous Side Effects

Recipients of metal-on-metal hips are at risk for developing serious side effects from the release of metal ions when the metal parts of the implant scrape together.  The metal ions can cause damage to the surrounding tissue which can lead to swelling, pain, difficulty walking and ultimately failure of the implant. The ions can also work their way into the bloodstream, causing damage to the patients’ organs and other debilitating side effects.  Patients with high metal levels have reported the following symptoms: chest pain, shortness of breath, numbness, weakness, change in vision or hearing, fatigue, feeling cold, weight gain and change in urination habits.  These can be symptoms of metallosis or metal poisoning.  Given the dangerous side effects associated with metal-on-metal hip implants, these hip implants are currently being investigated by the U.S. Food and Drug Administration (“FDA”).  The above problems with metal-on-metal hips are central to the claims alleged in each DePuy ASR lawsuit.

DePuy ASR Lawsuit – Flawed FDA Approval Process

One might reasonably ask how such a design flaw was overlooked.  Normally, before a medical device can be sold to the public, the FDA must approve it for safety and efficacy based on the results of clinical trials. The ASR implants, however, were cleared through a regulatory pathway known as the 510(k) process, which does not require clinical trials.  Medical device manufacturers can receive 510(k) market clearance for devices that are “substantially similar” to those already on the market.  DePuy claimed that the ASR was similar to the Pinnacle hips, which are also metal-on-metal implants also manufactured by DePuy.  However, among other differences, the Pinnacle was designed to fasten to a patient’s bone with screws, while the ASR devices rely on natural bone growth as a means of fixation.  Nevertheless, recent research suggests that both the Pinnacle and ASR devices are defective.  Although the Pinnacle has not been recalled, individuals experiencing hip replacement failure are also bringing lawsuits against DePuy.  In fact, the allegations contained in a DePuy ASR lawsuit are strikingly similar to those contained in Pinnacle hip lawsuits.

Both the Pinnacle and ASR devices received FDA approval through the 510(k) process.  If DePuy had been required to undergo clinical trials, the dangers associated with metal-on-metal hip implants could have been detected.  In addition to defective design, failure to perform adequate testing will be central in a DePuy ASR hip lawsuit.

Advice On Filing A DePuy ASR Hip Lawsuit

If you have been injured as a result of a DePuy ASR hip replacement product, contact one of our lawyers to help determine whether you are eligible to file a DePuy ASR lawsuit.

Published November 17, 2011 by