Twenty years ago the demands on hip and knee implants weren't as high as they are now. Usually patients in their 60s received implants at a point where they were less active in their lives now. Fast forward to today and those statistics have changed. Now people are getting implants at a younger age and with obesity levels rising, there is an increased strain on the implants as well.
So with all this in mind its not shocking that "nearly 10% of all hip and knee implants are revisions", says Leo Smit Business Director Implant Solutions of DSM Biomedical (Geelen, the Netherlands).
"The technology behind these replacements has progressed enormously, but the demand has increased even more so," Smit told Medical Device Daily.
Earlier this week the company reported that it is gaining ground with the development of a new polyethylene polymer platform geared toward improving mechanical properties and long-term stability of hip and knee implants through its cross-linkable ultra high molecular weight polyethylene (UHMWPE).
The company hopes to compensate for the increased strain on the implants and create a more long lasting product with less wear and tear.
It's a pretty tall task considering one of the main things the company has to prepare for is the body's natural ability to break down the components of the implants over a period of time.
"In the body you get an oxidized degradation of the material, Smit said. Particles often come from the implant and the body reacts to these particles. Eventually the bone surrounding the implant gets weaker because of the chemical reaction."
According to Smit, DSM's platform counteracts this because it incorporates small, highly reactive molecules that which produce the required cross-linking network at significantly lower radiation doses, which in turn lessen the adverse effects on the polymer's mechanical properties and allowing for stronger implants with better long-term stability. DSM Biomedical said that it is the first company to apply this technique to UHMWPE.
Cross-linking is a technique using high radiation doses that result in significantly improved wear resistance, but with adverse effects on the polymer's mechanical properties.
"Our idea was to still use crosslinking, but in a way that it would not have an adverse affect on the patient," he said.
Smit said the company began developing this particular platform nearly two years ago. Even though the polymer has been used for nearly 50 years in artificial joints, it was still clear that improvements in the material's wear and tear resistance were still needed to help avoid revision surgeries.
The company has filed a patent on this cross linkable UHMWPE platform and its application in total joint arthroplasty. It stated now that its research team has been able to demonstrate the easily cross-linkable behavior, the research is currently focusing on the optimization of the mechanical properties of the polymer. DSM Biomedical expects to be working closely with a number of the major orthopedic companies on the final development of the material.
The platform enters into a market where nearly two million people receive artificial hips or knees each year.
"Our hope is to have this polymer available for medical device companies to be able to put into their implants by the end of the year," Smit told MDD. "We want to make sure that we do all we can on our end to make sure that the polymer's help our customers get the proper approvals for their devices."
The company has been busy as of late and just recently reported that it has extended its lubricious ComfortCoat technology platform with the design of a hemocompatible antimicrobial coating to thwart intravascular catheter-related bloodstream infections (Medical Device Daily, June 1, 2009).
The ComfortCoat hydrophilic coatings are applicable for adhesion to a variety of substrates. The company said that it is its strong belief that this addition to the ComfortCoat technology platform is well suited for central venous and intravenous catheters, including PICC catheters that come into contact with blood and may remain in the body for several days.
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