Matthew Perrone, AP

Federal health experts said a device for repairing knees that was subject to a contentious, three-year review by the Food and Drug Administration is likely safe and effective, despite major shortcomings with company studies. The findings by the FDA's independent panel of orthopedic experts came despite the government's highly critical review of Regen Biologic's device published ahead of the meeting.

“There is evidence of reasonable efficacy, however we have concerns with the level of scientific proof,” said panel chairman Dr. John Kelly. The head of FDA's medical device division said the agency would make a decision on the device in coming weeks. The agency's options include leaving it on the market as is, pulling it, or it could call for additional testing.

The FDA is not required to follow the advice of its expert panels, though it often does. Regen Biologic's Menaflex device — an implant that reinforces damaged knee tissue — was cleared in late 2008 after three years of heated debate with regulators. FDA leadership decided to re-review the device last year after concluding the agency's approval was influenced by intense lobbying from congressmen in Regen's home state of New Jersey.

About 210 patients in the U.S. and 3,000 in Europe have had the Menaflex implanted. Regen asked the FDA in 2005 to approve its device under the 510k system, which allows speedy approval for devices that are similar to products already on the market.

Regen argued that the Menaflex was comparable to shoulder joint implants sold by Johnson & Johnson, Stryker and other companies. The device was ultimately approved based in part on those similarities, despite objections by some FDA scientists.

The FDA pressed its panel on the differences in design and function of shoulder and knee implants. Additionally, the agency asked panelists to comment on problems with Regen's study of the device, including missing follow-up data on patients.

While panelists agreed they would have liked to see more data on the device, they largely backed it as a safe and effective therapy. “It's the opinion of the panel that the Regen device overall has a favorable safety profile, however the panel has some concerns that the company's study does not fully fulfill the scientific method,” Kelly said.