Knee Implant Material Cleared by FDA

A new kind of polyethylene with improved resistance to wear, called Durasul, has been cleared by the U.S. Food and Drug Administration (FDA) for use in the Natural-Knee implants marketed by Sulzer Medica (Winterthur, Switzerland). A knee implant with Durasul could last longer than conventional knee implants. Sulzer is the first company to market the new technology for knee replacement.

Durasul was developed as a joint project between the Massachusetts Institute of Technology, the Orthopedic Biomechanics and Biomaterials research laboratory at the Massachusetts General Hospital (both in Boston, USA) and Sulzer Orthopedics. In extensive laboratory testing, Durasul has been shown to be more wear-resistant than the polyethylene commonly used in knee implants.

Over time, the continuous movement between the metal and plastic can cause the polyethylene in knee implants to crack, pit, and delaminate. This may cause microscopic particles to break off and be attacked by the body's immune system, leading to osteolysis, a loss of bone tissue that can lead to implant failure. Durasul was designed to solve the problems of delamination and wear. Previously, Durasul was cleared by the FDA for us in hip implants.