Stryker Rejuvenate Hip Implant and Wright Profemur Hip Implant Lawsuits Increase

The Stryker Rejuvenate Recall

The Stryker Rejuvenate and ABG II modular hip implant was recalled last month after less than two years on the market. The first Stryker Rejuvenate lawsuits were filed last week in New Jersey. The lawsuits allege that the Stryker Rejuvenate was defective in design.

The design of the Stryker Rejuvenate was cleared for marketing by the United States Food and Drug Administration (FDA) based upon Stryker's representation to the FDA that the modular neck design was already on the market. Stryker's application to the FDA to market the Rejuvenate cited the Wright Profemur modular neck as the predicate device that was already on the market to justify selling the Rejuvenate without conducting any clinical testing.

The Design of the Modular Implant Stems

Both the Stryker Rejuvenate ABG II hip implant and the Wright Profemur utilize a dual modular design. The traditional hip implant has two parts, a stem in the femur with a ball and a cup that is inserted in the pelvis. The design of the Stryker Rejuvenate and the Wright Profemur provide for interchangeable stems between the femur stem and the ball. This allows the surgeon to use a longer or shorter stem or a stem with a slightly different angle to get a better angle and alignment of the ball and the cup. Surgeons have always had a challenge with the two piece implants to get the leg length and the angle of force between the ball and the cup in the best position. So the theory behind these new interchangeable or modular stems seemed like a good idea. The problem is that they were rushed to market with little or no testing on people. They were tested in a laboratory and then sold and promoted as good products.

Corporate Profits More Important Than Patient Safety?

One of the big questions in the lawsuits against both companies is whether they put their interest in corporate profits ahead of patient safety. Lawsuits have been filed for several years against the Wright Medical Group based upon sudden and catastrophic failure of the modular titanium necks of the Profemur implants. On Friday August 3, 2012 Wright Medical Group received a subpoena from the United States Attorney for the Western District of Tennessee demanding company records on the Profemur from January 1, 2000 through August 2, 2012. Perhaps, this federal investigation will help answer questions about how this product could have been on the market so long with such a high failure rate.

Stryker will certainly have to answer some questions about how they justified marketing their product based upon the failing Wright Profemur stems. While the injury to patients from the two products is different the mechanism of the failure is similar. The injury to the Wright Profemur patients is sudden failure of the stem causing immediate pain and collapse necessitating an emergency room visit and surgery to replace the hip. The injury to the Stryker Rejuvenate patients is damage to the internal tissue of the hip from metallosis which may cause failure of the implant or the need for a new hip replacement. The micromovement, fretting and corrosion of the modular neck releases positively charged metal ions of chromium and cobalt which cause necrosis or the tissue. This is a similar injury to that caused by the DePuy ASR, Pinnace, Biomet Magnum, and Smith and Nephew R3 metal on metal hip implants.

Mechanism of Hip Implant Failure

Both of these failures are due to fretting and corrosion inherent in the design of the modular stem between the ball and the stem in the femur. Neither of these products was properly tested before marketing. Interchangeable modular stems were a potentially good idea that should have been properly tested before it was sold for wide public use. These defects could have been discovered and possibly corrected with proper testing and much pain and suffering could have been avoided.

The Lawsuits and The Federal Investigation

The pending lawsuits from injured patients will provide compensation and will answer questions about what Stryker and Wright knew and when they knew it. I know for many of my clients with these hips the lawsuits are about more than just compensation. People want to know how these dangerous products could be sold without proper evidence that they were safe. Apparently, now the federal prosecutors in the U.S. Attorney’s Office in Tennessee are also interested in finding the answers to these questions as well.