30 Year Knee Technology (Verilast)
Total Knee Replacement using VERILAST™ Technology
Background Information
Quick Facts about total knee replacement
• Roughly 400,000 total knee replacements are performed each year in the United States
• All total knee replacements consist of a three-part system: a metal tibial component, a metal femoral component and a plastic insert between them.
• A common issue with knee replacements is what surgeons refer to as “wear.” As the surfaces of the implant rub together, tiny fragments of plastic and metal material wear off.
• Implant wear accounts for one reason why knee implants can fail, and why a patient may undergo repeat surgery years after the original procedure
– One recent study found that in a group of knee implants that were “revised” after an average of 7 years of use, 44% of the cases were the result of plastic wear.
• The consensus of scientific literature is that knee replacements are expected to last between 10 and 15 years before wear becomes an issue.
What is VERILAST Knee Technology?
VERILAST Technology is a pairing of materials that is shown in laboratory testing to more than double the wear performance of the Smith & Nephew LEGION™ cruciate retaining (CR) knee replacement.
• It is the combination of Smith & Nephew’s award-winning OXINIUM™ metal alloy and a “cross-linked” plastic component (XLPE).
• VERILAST is a knee replacement technology that uses advanced, low-friction surfaces for both sides of the knee joint.
VERILAST Knee Technology’s unprecedented testing
• The LEGION™ CR knee replacement made with VERILAST Knee Technology is the only knee tested for 30 years of wear performance
• Smith & Nephew has performed more than 2 ½ years of continuous laboratory-based wear testing on its LEGION CR knee replacement made with VERILAST Knee Technology.
• During this testing, the implants were subjected to 45 million cycles, or steps, on a wear simulator.
– Forty-five million cycles is equivalent to 30 years of an active adult’s life under typical conditions.
– Each cycle loaded the knee implants with 585 pounds of pressure, or an industry standard of 3.2 times the typical body weight of a knee replacement patient (185 pounds).
– During the same test, a similar knee made from conventional materials—cobalt chrome and standard plastic—were submitted to wear testing, as well.
• The results of the testing were remarkable.
– 98% Wear Reduction: After 5 million cycles, the LEGION CR Knee with VERILAST Knee Technology reduced 98% of the wear that was generated by the other, traditional implant materials.
– 81% Wear Reduction: When the LEGION CR Knee with VERILAST Knee Technology kept “walking” out to 45 million cycles, it still reduced 81% of the wear generated by the conventional material knee implant that was stopped after the first 5 million cycles.
About VERILAST Knee Technology
Based on laboratory wear simulation testing, the LEGION◊ Primary Knee System with VERILAST Technology is expected to provide wear performance sufficient for 30 years of actual use under typical conditions.
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, such as bone structure, 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.
What is OXINIUM™ (Oxidized Zirconium) material?
• OXINIUM Oxidized Zirconium, a tough, smooth metal whose ceramic surface is 4,900 times more abrasion resistant than cobalt chrome. The ceramic surface is created through a manufacturing process where oxygen is naturally diffused into the zirconium metal as it is heated in air. When the metal is saturated with oxygen, the surface transforms from a metal to a ceramic. This is a transformation of the original metal surface into a ceramic and not an externally applied coating.
• OXINIUM is a hypoallergenic implant material available for femoral-side knee implants. Other implant materials (primarily cobalt chrome) contain nickel and chromium, two metals associated with metal allergy. If patients have an allergic reaction to their cobalt chrome knee implant, it may have to be surgically removed.
• OXINIUM is more than 20% lighter than a same-sized implant made from cobalt chrome—the other metal from which knee implants can be made.
• OXINIUM received the 2005 ASM International Engineering Materials Award for its innovative design.
• Since 2001, more than 200,000 OXINIUM knee implants have been implanted worldwide.
About knee replacement
There are potential risks with knee replacement surgery such as loosening, fracture, dislocation, wear and infection that may result in the need for additional surgery. Do not perform high impact activities such as running and jumping unless your surgeon tells you the bone has healed and these activities are acceptable. Early device failure, breakage or loosening may occur if you do not follow your surgeon’s limitations on activity level. Early failure can happen if you do not guard your knee joint from overloading due to activity level, failure to control body weight or accidents such as falls. Knee replacement surgery is intended to relieve knee pain and improve knee functions. Talk to your doctor to determine what treatment may be best for you. Additional information available at www.RediscoverYourGo.com or 888-825-2062.