What Happened to the FDA Request for More Hip Implant Studies?

Hip arthroplasty devices have been available in the U.S. for over 50 years with a variety of outcomes. An artificial hip medical device may be used to restore function of the joint, relieve pain or cure a disease or condition not responsive to a more conservative therapy.

In May 2011, the U.S. Food and Drug Administration (FDA) sent out 145 orders to 21 manufacturers of metal-on-metal (MoM) hip systems to find out why so many were failing prematurely due to pain, swelling, loosening, tissue necrosis, and metallosis.

The FDA has the authority to order what’s called a 522 study, which is the postmarket surveillance of a device after it’s already implanted. That’s because in most cases, the thousands of medical devices approved every year do not have to go through premarket approval requiring the submission of clinical studies to prove safety and effectiveness before a device is marketed.

As unbelievable as that sounds, that is the “hands-off’ way the FDA monitors medical devices. And to add insult to injury, under section 522 of the Federal Food, Drug and Cosmetic Act, postmarket studies are “conducted effectively and efficiently and in the least burdensome manner.”

“Least burdensome” might refer to the consumer or patient, right? After all, the agency is there to protect the public. But don’t be too optimistic. “Least burdensome” actually refers to the medical device manufacturer – not the patient who may have suffered injuries associated with that medical device. The FDA does not want its requests for safety studies to present too much burden to the manufacturers.

Finally in May 2011, the hip manufacturers, primarily metal-on-metal (MoM) hip makers, were asked to submit protocols to study specific safety issues related to MoM devices including why so many were failing prematurely due to metal ion concentrations in the bloodstream.

So far, those studies and their results are nowhere to be found.

Looking on the FDA’s website, some of the studies are listed as “Other” while others say “Plan Overdue” or “Progress Adequate,” or “Pending.” For Stryker the majority of the studies say “Terminated,” and for Wright Medical, the metal ion level studies say “Plan Overdue.”

The FDA says a “Plan Pending” just means the FDA has not yet approved the study plan; a “Plan Overdue” means it’s been six months or more since issuance of the 522 order and the FDA has not yet approved the study plan. “Other” means the device is being redesigned or a change in ownership is underway. This is an interim study status.

Regardless, the FDA orders postmarket studies after the fact – and then does not even assure the companies are in compliance with the order?

Since we are 18 months past the 522 study request and countless numbers of metal-on-metal and modular hips continue to be implanted – where is the urgency? Where is the priority of patient safety? Who is the FDA supposed to be protecting?