While thousands of people may consider the recalled ASR hip replacement wicked because of problems with loosening, metal debris and a host of other issues, we never expected it to actually have evil horns! So how did the ASR 300 end up with spikes coming out of it? And what are they for? Here’s what we know.
On October 29, 2007, two years after getting FDA premarket approval for the ASR hip implant system, DePuy returned to the FDA for approval of a newer version of their ASR line. DePuy claimed that new version, the ASR 300 was comparable to the original ASR except for one design change: Three spikes were added to the top of the acetabular cup. But in the application, DePuy isn’t clear about why they would need to change the ASR design. Here’s a quote that attempt to explain it:
“The cups feature three spikes for adjunct fixation and are available in ten sizes. The subject device is identical in design to the acetabular cups cleared as part of the DePuy ASRTM Modular Acetabular Cup System in K040627 on August 5, 2005 with the addition of spikes on the outer surface of the cup.”
The executive summary of the new product goes on to further describe the role of the three spikes, explaining that “the spikes are intended to pierce the bone of the acetabulum and provide immediate fixation in addition to the interference (frictional) fit achieved by underreaming the acetabulum.”
As amusing as the x-ray photo may look, the very serious problem with this product is in the approval process. It required no performance testing before going on sale because this hip device was not an entirely new product, only a modification of the existing ASR acetabular implant. As a modification, it was classified under the special provisions of the 510(k) process. But that’s not all. The original ASR implant was also given premarket approval using the same 510(k) process.
The question really should be “how many times can you adapt and revise a previously approved medical device before it’s no longer the same product that was originally approved?”
By the way, the ASR 300 is also among the line of DePuy hip implants recalled last year worldwide.
For more information about the DePuy ASR hip recall, contact us at 888-952-5242 or fill out the form on this page.