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NEWS & FEATURES

New Total Knee Replacement Available
Oxinium Knee Offers Pain Relief For Younger Patients

Dr. Kenneth Krumins, MD

There are more replacement operations performed on the knee than any other joint in the body. While more than 209,000 people, mostly over age 65 have total knee replacements each year, 27% of patients are in the age range of 18-64 with that percentage growing. Previously, many patients in their early 50s or younger had been warned not to undergo this surgery since normal use and wear offered a shorter life expectancy for the knee. This resulted in the need for more surgeries as patients grew older while their bones grew weaker.

Unfortunately, there are more patients with severe knee arthritis earlier in life; often the result of athletic knee injuries in teens, 20s, and 30s. Until now, these patients were advised to postpone the replacement surgery and live with the pain. The new Oxinium knee will offer dramatic pain relief to patients in their late 40s and early 50s and will hopefully last much longer than conventional total knee replacements.

What makes the Oxinium Knee different?

The knee replacement prostheses that have been used for over the past 20 years are made of a plastic liner component and metal 9cobalt chrome alloy) femoral component. It is estimated that these knees last about 12-15 years. The new oxidized zirconium knee consists of a plastic liner component and a metal (zirconium alloy) femoral component with a life expectancy of 20-25 years.

Life expectancy of the replacement is based on the wear of the joint, which is a result of the plastic liner and femoral components rubbing against each other. By changing the femoral component from metal to oxidized zirconium, the studies have shown that the wear is 80 times lower than seen with traditional cobalt chrome alloys rubbing against plastic. A lower wear rate means that the implant has a longer potential life expectancy.

Other advantages of the Oxinium knee are:

It is scratch-resistant whereas cobalt chrome alloy can develop small microscopic scratches in the metal. These scratches, when rubbing against the plastic liner component, can cause even greater wear.

Furthermore, an oxidized zirconium surface is more "wettable" making for a smoother articulation with the plastic. This too leads to reduced wear rates.

Another advantage is that the material is extremely bicompatible. There are some patients, who have allergies to nickel, which is a constituent of the cobalt-chrome type alloys traditionally used for total knee components. As a result, patients with severe allergic reaction to nickel were unable in the past to receive total knee prostheses. The oxidized zirconium alloy implant contains no nickel so it can be safely used for these patients.

The Oxinium Total Knee Replacement is now available in the Central Florida area at the Florida Hospital Orthopaedic Institute of Excellence in Winter Park, Florida.

For more information contact Dr. Kenneth Krumins, who is currently involved in ongoing clinical trials using the Oxinium Total Knee Replacement. Dr. Krumins is an orthopaedic surgeon specializing in arthroscopic and reconstructive surgery of the knee at the Jewett Orthopaedic Clinic in Winter Park, Florida.