May 27, 2009

FDA OKs new total ankle replacement system

The U.S. Food and Drug Administration has approved a total ankle replacement system for arthritic or deformed ankles that may preserve some range of motion.

The federal agency said the new prosthesis, the first of its type, is a mobile-bearing device, which relies on bearings that move across a surface of polyethylene, a flexible plastic.

Once arthritis or injury destroys the cartilage that cushions the ankle bone, the joints can become painful enough to warrant total ankle replacement.

The newly approved Scandinavian Total Ankle Replacement System is an alternative to fusion surgery and may allow for greater rotation and movement in the joint, the FDA said.

Fusion surgery involves cementing the tibia (shin bone) -- the thicker of the two bones in the lower leg "“ to the talus bone in the ankle, FDA officials said. The procedure stabilizes the ankle, but significantly decreases the ability to move the foot up and down.

This device offers another treatment alternative to fusion surgery, and more closely imitates the function of a natural ankle, said Dr. Daniel Schultz, M.D., director of the FDA's Center for Devices and Radiological Health.

As a condition of FDA approval, the company will evaluate the safety and effectiveness of the device during the next eight years.

The new system is owned by Small Bone Innovations Inc. of Morrisville, Pa.