Virtually all total knee replacement systems use a combination of metal and plastic components to replace the surfaces of a damaged knee. Metal is typically used to replace the surfaces of the bone, while plastic is most commonly used to replace the joint's cartilage.
Unfortunately, the metal and plastic surfaces of an implant can wear down over time. The primary cause of this "implant wear" is the friction created when the upper, metal, part of an implant - called the femoral component - rubs against the plastic insert. Even with pristine implants, over time, this friction can cause tiny particles of the insert to wear away. If the metal component becomes scratched for any reason, this destructive process can be increased dramatically. In fact, this type of implant wear is a leading cause of premature knee replacement failure.
Fortunately, implant wear can be offset by using advanced, wear-reducing materials during the creation of the implant.
Unlike other implants that only available with cobalt chrome for their metal femoral components, the JOURNEY II Active Knee implant can also be made with a proprietary metal alloy called OXINIUM◊ Oxidized Zirconium. While cobalt chrome has been used successfully for years, laboratory tests have shown that the "ceramicized" OXINIUM metal alloy is twice as hard as cobalt chrome and can be twice as resistant to the type of scratching that can cause implant wear.1 First introduced in 1997, OXINIUM implants have been used in more than 1 million surgeries around the world.
And since each implant is a combination of metal and plastic, JOURNEY II implants also use a harder, highly cross-linked polyethylene known as XLPE for the plastic insert.
Working together, these materials form a bearing surface combination known as VERILAST Technology, which is unique to global medical device maker, Smith & Nephew.
VERILAST Technology has been designed to address "wear and tear," which is only one reason why a knee implant may need to be replaced. Listen carefully when your orthopedic surgeon reviews other risks that can shorten the life of your new knee - such as infection, excessive weight gain or high impact sports.
The results of laboratory wear simulation testing have not been proven to predict actual joint durability and performance in people. A reduction in wear alone may not result in improved joint durability and performance because other factors can affect joint durability and performance and cause medical conditions that may result in the need for additional surgery. These other factors were not studied as part of the testing.
Individual results of joint replacement vary. Implants are intended to relieve knee pain and improve function, but may not produce the same feel or function as your original knee. There are potential risks with knee replacement surgery such as loosening, wear and infection that may result in the need for additional surgery. Patients should not perform high impact activities such as running and jumping unless their surgeon tells them that the bone has healed and these activities are acceptable. Early device failure, breakage or loosening may occur if a surgeon's limitations on activity level are not followed.
Talk to your doctor to determine what treatment may be best for you.
1. G. Hunter and M. Long, "Abrasive wear of oxidized Zr-2.5Nb, CoCrMo, and Ti-6Al-4V against bone cement," 6th World Biomaterials Cong. Trans., Society for Biomaterials,Minneapolis, MN, 2000, p. 835.
The information listed on this site is for informational and educational purposes and is not meant as medical advice. Every patient's case is unique and each patient should follow his or her doctor's specific instructions. Please discuss nutrition, medication and treatment options with your doctor to make sure you are getting the proper care for your particular situation.