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STAINS ON SURGICAL INSTRUMENTS

July 23, 2009

Good Morning;

I'm sending this message from Turkey. Our company is one of the leading manufacturer of orthopedics implants (hip, knee etc.) I want to share with you one of our major problem.

Our instruments, which have been using during the surgeries, have some surface quality problems. After those surgeries, those instruments are heated at autoclave furnaces for sterilization.(134 C for 45 min)

So far so good but after autoclaving we have some stains problems on the stainless steel. Those are mostly water drops stains. Probably hospital doesn't use distilled water during sterilization on autoclave. But unfortunately we cannot manage to get rid of those stains after basic chemical applications.

So I think maybe anti-finger coatings could be helpful to us. But the problem is I don't know whether your coating is bio-compatible or not? Or mechanical properties are good enough to resist during the surgery. (For example screwdriver is one of our instruments and it'll expose force during the surgery).

But most important question this coating can stop those stains? Because those coatings are hydro-phobic. So in theoretically no stains should remain after sterilization even there is hard water minerals at autoclave.

Or the other solution could be enzyme-detergents (All-in one). I read an article and it says it's very efficient way to get rid of those stains.

And lastly I wonder ultrasonic cleaners could be enough for this maintenance.

Actually I suppose all of those steps are required for a perfect cleaning.

I'll be glad if you can help about this issue and show me a way.

Please criticize my suggestions above or offer a new idea. But especially what do you think about coating idea?

Nedim Levi
Materials Engineer - Istanbul, TURKEY

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July 28, 2009

Also I'd like to inform you that our raw materials for those instruments are 304 and 420 SS. But mostly 420.

Now we're thinking of replace this steel with PH 17-4. But I still assume there'll be those kind of stains due to nature of water. ( As I mentioned most of the hospitals prefer to use tap water). Furthermore our polymeric raw material is Polyoxymethylene Copolymer (POM). Stains are occurred on those polymers as well.

So I'll be glad if you show me a way for surface finish?

I have 3 solution proposal as I mentioned above.

1. Hydrophobic Coating (Just for one time)
2. Ultrasonic Cleaner (For Permanent Maintenance)
3. All-in One Enzyme-Detergent (For Permanent Maintenance)

Do you think any other resolving path? Or any correction?

P.S. There's a passivation layer on our SS for corrosion protection. Do you think it'll effect coating quality? Or a hydrophobic or another kind of coating can also works as a passivation layer besides its major function?

Nedim Levi
- Istanbul, Turkey

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Why not use titanium?

It may cost more, but it's more than biocompatible; moreover, the oxides which will form expose a photocatalytic anti-bacterial effect.

Robert H Kinner
- Toledo, OH United States
July 30, 2009