Knee Implant Technology Lab-tested for 30 Years of Simulated Wear Performance

KGH Now Offering Lighter Weight, Wear-resistant Knee Implant

For years, orthopedic surgeons have cautioned knee replacement patients with the same warning - any implant can fail after years of use, and if that happens, it has to be revised. While that message is still true, the likelihood of a patient's knee implant failing due to normal wear has been dramatically reduced thanks to VERILAST? Knee Technology, which is offered by surgeons at Kennewick General Hospital.

"Every year, I see a growing number of younger, active adults with severe arthritis that require knee replacement surgery," says Michael Sherfey, D.O., co-medical director of KGH's Joint Replacement Center. "Unfortunately, one of the major drawbacks for these physically active patients has always been the potential that they would wear out their implant. When that happens, a second surgery and recovery is usually necessary."

Made up of three main parts, all total knee implants consists of a plastic insert positioned between two metal components. Over time, the movement of the metal component sliding against the plastic insert can wear down the plastic and cause it to fail. In some cases, tiny particles of the plastic can accumulate in the joint resulting in a condition known as osteolysis, or the softening of the bone around the joint. When this happens, the implant may shift or loosen, which leads to pain and instability in the joint.

Unlike other knee implants, made from cobalt chrome metal and a high-density plastic, VERILAST technology is made from a proprietary metal alloy called OXINUM? Oxidized Zirconium and a highly cross-linked polyethylene. By combining these two low-friction materials, a knee implant with VERILAST technology can significantly reduce the kind of wear that can cause an implant to wear out before its time.

In fact, extensive laboratory testing by orthopedic implant manufacturer Smith & Nephew (S&N), the creators of VERILAST technology, has shown some impressive results. The "knee" was subjected to the equivalent of 45 million steps or approximately 30 years of an active adult's life under typical conditions.

After 5 million steps, the S&N knee reduced wear by 98 percent compared to a knee made with the traditional implant materials. At the 45 million mark, the S&N reduced 81 percent of the wear when again compared to the 5-million-cycle knee implant made from traditional materials. It is the first knee implant to be lab-tested for 30 years of simulated wear performance, more than double the length of other tests.

"Physically active patients want to end their knee pain for good," says Dr. Sherfey. "I want to offer my patients a knee implant that lasts and I'm pleased VERILAST technology has been wear tested out to 30 simulated years for a market that views 10 to 15 years as the gold standard. This could be a generational leap forward for active patients, not just an incremental improvement.

"For a younger, more active patient, this makes perfect sense. They get the pain relief they need, the mobility they want and the potential for improved longevity of the implant."