Because Americans are living longer, more active lives than previous generations, the need for joint replacement surgery has never been greater.

metal-knee-jointIn fact, according to the Mayo Clinic, about one million patients get new hip or knee implants each year in the U.S.

So, where do all these artificial joints comes from? A small but growing industry, medical device manufacturers specialize in precision machining of implantable devices, surgical instruments, and diagnostic equipment. And a critical part during the manufacturing of these devices is cleaning, which is where we come in.

The Costs  

It might surprise you to learn that hospitals pay an average of $8,000 for an artificial hip. The high price tag is due to the fact that the materials and equipment that are needed to make these implantable devices are extremely expensive.

For example, porous metal, or titanium foam, is a material that improves osseointegration of the components in hip replacement, knee replacement, and dental implants. In other words, it helps facilitate metal-to-bone bonding for a better overall solution. The only problem is that this material is extremely difficult to clean.

Dirty Cleanup

Think of the porous implant as a sponge that soaks up and traps all the contaminants and oils created during manufacturing. Pictured is a representation of a zoomed in part showing the contaminants in the pores. The bone tissue needs to grow into the pores of the implantable device, but for the two to bond properly, the porous metal must be incredibly clean. If there is any contamination at all, the bone will be rejected and the joint will not perform its purpose, with the possibility of causing an infection.

Although it might be a bit cleaner than the standard auto assembly line, making artificial hips and knees still requires a manufacturing process. The oils and coolants that are used during the machining process are sometimes very difficult to remove using conventional cleaning methods. That is why many medical device manufacturers are making the switch from aqueous, water-based, to CO2 cleaning.

What’s the Difference?

Aqueous based cleaning methods use water to remove bacteria, spores, or mold that can be trapped in the geometry of a medical device. Especially when dealing with porous metal, water remains in the spaces or holes of the structure, which can lead to rejected implants. That is not an issue with carbon dioxide cleaning, since the liquid CO2 evaporates, leaving the part dry and clean.

How Does it Work?

When stored under pressure, carbon dioxide can be kept in a liquid state. This liquid CO2 is an excellent cleaner for porous structures because it gets into small crevices and blind holes difficult for water to reach. Cool Clean Technologies, LLC LCO2 cleaning system uses a series of rinses with liquid CO2, removing light oils, and resin. After the cleaning cycle is complete, 95% of the CO2 is recaptured. The pressure is removed from the chamber and any remaining CO2 left inside the part evaporates. Because there is no water or hazardous solvents involved, the waste stream for your company is considerably less using CO2 cleaning.

As popular as they may be, traditional cleaning methods that use water and solvents are wholly inadequate for the needs of contemporary medical device manufacturers. Liquid carbon dioxide or LCO2 is the only solution that eliminates the use of water for environmentally conscious cleaning.