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
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
"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."