Metallosis Linked To Metal on Metal DePuy ASR Hip Implant

Metal-on-Metal Bearings
It has been well-documented that thousands of patients with DePuy ASR hip implants have had to undergo revision surgery. That fact is revealed on Johnson & Johnson’s website. DePuy is a subsidiary of Johnson & Johnson. What isn’t revealed on the website however, is that metallosis has been linked to the DePuy metal-on-metal implants. Metal-on-metal bearings were introduced as a better alternative to ceramic or plastic bearings. The problem is that poorly designed bearings can create severe complications, like metallosis.

What is Metallosis?
According to the Journal of Bone & Joint Surgery, metallosis is aseptic fibrosis, local necrosis or loosening of a device secondary to metallic corrosion and release of wear debris. Metallosis occurs when the metal-on-metal movement of the hip implant causes friction and releases potentially dangerous levels of chromium and cobalt ions into the body. This condition can result in nerve damage and rashes. It can also require the need for corrective surgery.

Why do DePuy ASR implants Create the Risk of Metallosis?
The problems with the DePuy bearings appear to stem from the design. The DePuy ASR hip replacement was made with a poorly designed cup and socket that did not fit together properly. In addition, the implant is shallower than most other hip replacement systems, which made it much more challenging to implant than other systems. These design issues have greatly increased patients’ exposure to metallosis. The serious metallosis risk makes one wonder how Johnson & Johnson determined that metallosis didn’t even deserve a brief mention on its website? It also raises the question whether the risk could have been prevented?

Did DePuy Wait Too Long?
DePuy didn’t recall the product until after more than two years of complaints. Dr. Stephen Graves, the director of the Australian medical device registry, said that the company was too slow in pulling the device from the market. The device’s co-developer, Dr. Thomas Schmalzried, said he and DePuy officials realized that the ASR cup might be more of a challenge to implant properly than competing cups. "The window for component position that is consistent for good, long-term clinical function is smaller for the ASR," than other cups, Schmalzried said. Schmalzried reported that he received $3.4 million from DePuy for his work on the ASR and other devices.

Conclusion
It is obvious that the risk of metallosis associated with the DePuy ASR hip implants was high. It is also clear that metallosis can be debilitating and should not be taken lightly. Yet DePuy discarded those risks and ignored more than three years of complaints before pulling the defective implants off the market last August. Those patients with DePuy implants have been harmed and they deserve to know they have legal rights and remedies.

The law firm of Childers, Schlueter & Smith, LLC continues to investigate DePuy ASR Hip Implant claims on behalf of patients who received the defective ASR hip implants.