Instrument care in medical foot care

Instrument care

Instruments are an essential part of a practice's equipment. Careful maintenance and correct handling make sure you can enjoy them for many years.

Almost all nippers, scissors, scalpels, tweezers and octagonal instruments used in medical foot care today are made of stainless steel (rustproof – stainless steel – Inox).

Many people wrongly assume that stainless steel is an indestructible, permanently durable material. In fact, stainless steel instruments are exposed to very different forms of attack (physical, thermal, chemical). If they are not cared for properly, these steels are only partly resistant to chloride ions (aggressive water). Chloride ions mainly cause pitting corrosion, but also stress corrosion cracking. The greatest risk comes from water in which larger amounts of common salt (sodium chloride) are dissolved. So what should you watch out for?

1. Disinfection and cleaning

There is a risk of rust. Please do not put nickel-plated or chrome-plated instruments through wet disinfection. Even though drinking water quality is good today, it can contain a high concentration of dissolved substances, which can damage instruments during wet disinfection and cleaning. Excessive levels of harmful substances in the water (sodium chloride) speed up pitting corrosion. We therefore recommend fully demineralised water, in other words distilled water.

Instruments should be disinfected and cleaned immediately after use wherever possible; this prevents residues from drying on. Combined disinfectant and cleaning agents must be used. Always follow the manufacturer's instructions on contact time and concentration.

Important: After taking the instruments out of the disinfectant bath, dry them carefully.

2. Ultrasonic cleaning

For cleaning in an ultrasonic bath, instruments must be placed open in special mesh trays. The cleaning solution must be changed regularly as specified by the manufacturer. Instruments cleaned by ultrasound must always be rinsed thoroughly afterwards with clear water, ideally with fully demineralised water (distilled water).

Important: Dry the instruments carefully after rinsing.

3. Care

Care means applying lubricants. We recommend a care spray on all joints and moving parts (nipper and scissor joints). This prevents metal abrasion, which can lead to corrosion. Alongside its excellent lubricating properties (synthetic oil does not gum up), the oil also repels (displaces) water if any moisture is left.

4. Instruments and hot-air sterilisers

Make sure the sterilisation temperature of 180 °C is maintained. If the temperature is exceeded, the steel can lose hardness and instruments may discolour. Bear in mind that the temperatures in the steriliser create stresses in the steel (heat expands). To avoid stress corrosion cracking, instruments with locks should only be sterilised in the open position.

When opening the hot-air steriliser, make sure the condensation effect (warm inside, cold outside) does not settle on the instruments as clouds of steam. Risk of rust! Always let instruments cool down thoroughly. Unless supplied sterile-packed, brand-new instruments must always be cleaned thoroughly and sterilised before first use. The same applies to instruments that have been in the workshop for repair.

5. Corrosion and surface changes

Most people have been annoyed at some point by discoloured, rusty or stained instruments. Discoloured surfaces are often called rusty. They appear above all in places that are hard to reach, for example on scalpel handles with replaceable blades, behind nipper springs, and in the joints of nippers and scissors. The cause can be contamination of the surface or cleaning solutions that have been used too often.

If instruments are left in disinfectant solutions for a long time and are not rinsed very thoroughly, residues burn on during the subsequent sterilisation and discolour noticeably. Over time this can lead to rust (pitting).

To prevent surface corrosion, avoid strongly acidic and alkaline cleaning agents wherever possible.

6. Instruments with damaged surfaces

Stainless instruments in perfect condition must never come into contact with instruments whose surface is damaged (for example old sets, or instruments with a flaking nickel or chrome layer). To avoid the contact corrosion this causes, damaged instruments must be sorted out.

Further reading: Instrument reprocessing in podiatry · Rust stains on instruments · Rustproof, nickel-plated, stainless steel