About two dozen lawsuits have been filed around the country alleging that Zimmer NexGen knee replacements are defective and the company failed to warn that they have a high rate of failure requiring additional revision surgery.
Last week, plaintiffs' lawyers filed a petition to consolidate the cases before a multidistrict litigation panel. That petition is scheduled to be heard in July.
Randi Kassan, a plaintiffs' attorney with The Sanders Law Firm on Long Island, said her firm first noticed an uptick in Internet complaints around the knee replacements and has been looking into claims for over a year and a half.
"We started seeing tremendous Web and blog activity where patients were voicing their concerns with their replacement knees and it sent up a signal to us that something was very wrong," said Kassan.
Her firm filed the first lawsuits in federal court in Illinois, Minnesota and Nevada.
The suits claim that the family of products known as NexGen knee replacements, advertised as providing greater flexibility once the knee replacement is implanted, have a greater risk of loosening and no greater benefit in flexibility than other designs.
A number of suits claim that in 2010, Dr. Richard Berger, a Zimmer consultant, presented a paper to the American Association of Orthopedic Surgeons showing that about 9 percent of patients who had NexGen implants required revision surgery and that 36 percent of patients showed signs of loosening within the first year.
According to Ronald S. Goldser, of counsel to Zimmerman Reed in Minneapolis, which has also filed cases in federal court, when the knee replacement comes loose it generally requires a redo, but a second implant surgery is more invasive and much less likely to succeed.
"You're already dealing with someone with less bone and who already has significant pain complexes," said Goldser, adding that lawyers are continuing to evaluate these claims.
As litigation picks up and more law firms have begun advertising for potential clients, the manufacturer of the products, Zimmer Holdings, is going on the offensive.
In February, the company sued four plaintiffs' law firms for "false and misleading" statements about its products, according to Garry Clark, a spokesperson for Zimmer, which is based in Warsaw, Ind., and has the leading market share of knee replacement products in the U.S.
"The [law firm ads] used false terminology about phantom recalls," said Clark. He said that although certain package labeling in the family of NexGen products has been recalled, the ads made statements about components that have not been recalled.
Those suits settled, and according to a website the company created to discuss the lawsuits, the four law firms — Pulaski & Middleman in Houston, Texas, Kresch Legal Services in Southfield, Mich., Gordon, Edelstein, Krepack, Grant, Felton, Goldstein in Los Angeles, Calif., and Weller, Green, Toups & Terrell in Beaumont, Texas, — printed retractions on their websites saying that the sources they relied on don't support statements that significant numbers of patients experienced pain or loosening or required additional surgery or that the products were defective.
After those cases settled, the company expanded its lawsuit in May to go after three more plaintiffs' law firms for false and misleading statements, according to Clark.