It’s Harder to Replace a Knee Than a Crumpled Fender

Washington, DCWhen artificial joints were more simplified, manufactured with more traditional materials and were subject to a Premarket Approval (PMA) by the US Food and Drug Administration (FDA), such medical devices were expected to last upwards of 15 years, and most did. Revision surgeries were either rare or you never heard about them because they were not an issue. That’s not the case today, as anyone experiencing Zimmer Persona Knee pain can attest.

Zimmer is but one of several manufacturers having to recall a component due to early failure - many of which have been manufactured with updated materials or designs that allowed the devices to be approved through the FDA’s fast-track 510(k) Clearance. The latter spares the manufacturer from the costs and delays associated with conducting intensive clinical trials before a device is allowed into the market. With the 510(k), the device is approved provided it holds substantial equivalency to devices already on the market and with a PMA in place.

The Zimmer Persona Knee is an example of a device approved and fast-tracked to market through a 510(k) Clearance, and appeared to perform well save for one particular component: the Zimmer Persona Trabecular Metal Tibial Plate, which proved to be problematic and was subject to a Class II Zimmer Persona Recall in February of last year. The recall was triggered following substantial reports of loosening of the knee, and an increase in radiolucent lines on X-rays that suggested a gap between the metal plate and the bone.

All lots and sizes of the Zimmer Persona Trabecular Metal Tibial Plate were recalled and ordered off the market. “Urgent Medical Device Recall notices were issued to affected distributors, hospitals, and surgeons on 2/16/2015 via mail,” the FDA said in its recall notice in March 2015. “Customers are asked to review the notification and ensure affected personnel are aware of the contents. All affected product are to be located and quarantined immediately.”

That’s 11,658 devices not including those already implanted. Those devices still in service were either beginning to fail early and contributing to Zimmer Persona Knee pain - or leaving patients with prior knowledge of what kind of knee implant they had, wondering if their medical device would beat the odds and continue working.

Many plaintiffs have filed a Zimmer Persona lawsuit over the failure of the component, but also over the need for revision surgery. The latter can be a complex procedure, as bone already revised for the failed implant would potentially have to be revised a second time for a replacement medical device. It can be a challenge for both the surgeon and the patient, who must now endure a second round of convalescence, and in many cases, physiotherapy, so soon after the first. This can impact the livelihood of the patient, who must potentially take additional time away from work.

Given the complexity of surgery in general, artificial joints were originally designed to last 15 years under normal use. That’s the expectation of both surgeon and patient, given that human physiology is not nearly as adaptive as machines when a part wears out and has to be replaced. With an appliance, once a repair is undertaken, the machine is ready to return to immediate service.

Humans, on the other hand, require time to heal.

With the aging US population - and especially baby boomers generally having adopted a more active lifestyle than previous generations - medical device manufacturers have stepped up their competition for market share by introducing updated designs and materials meant to allow for a more active lifestyle, and for those artificial joints to last beyond 15 years.

It appears, however, that most have been released to the market through the FDA’s 510(k) Clearance.

And many, including the Zimmer Persona Trabecular Metal Tibial Plate, are failing much too soon, triggering in many cases a Zimmer Persona lawsuit.