What are Surgical Instruments made of? Composition of Alloys used to manufacture Surgical Instrument
What are surgical instruments made of?
Most surgical instruments are manufactured using stainless steel. The highest quality instruments that can be used to perform human surgery are referred to as ‘surgical grade instruments’. Other grades, that are lower in quality, are commonly termed the ‘economy grade’ or the ‘floor grade’. Steel can be hardened by the use of carbon. More than a dozen different types of stainless steel are used to manufacture surgical instruments. Steel to manufacture a particular instrument type is selected based on the required hardness, tensile strength, flexibility and malleability.
In today’s globalised world, it is a very common practice to use steel obtained from another country to manufacture instruments at the local level. Hence, quality of instruments is inconsistent and poorly manufactured instruments are available in different markets of the world.
The steel used for manufacturing surgical instruments contains chromium in addition to iron ore. This steel is usually a corrosion resistant alloy, which possesses extreme strength and durability. The ‘stainless’ properties of steel are related to the amount of chromium present in a particular steel sample. The chromium present in a steel sample forms a thin layer on its surface, which becomes the 'passive' layer that prevents corrosion. Although this layer of chromium is invisible, it renders the instruments corrosion-resistant with repeated use.
Different alloys that make up surgical stainless steel contain iron ore, carbon, nickel, chromium, manganese and some other metals. Generally speaking, high quality surgical instruments contain a greater percentage of chromium, which bestows greater ‘passivation’ to the alloy. As a result, the metal becomes less reactive and becomes more resistant to corrosion. Poor quality steel lacks this quality and for this reason develops ‘hairline fractures’ upon repeated use.
Hairline fractures may not be visible to the naked eye; hence magnification may reveal their presence upon close inspection. The size of hairline fractures increases with repeated use, ultimately causing the surgical instrument to break. Some poor quality instruments may demonstrate ‘flaking’ as they get old. Microscopic irregularities on the surface of surgical instruments can affect delicate body tissues; this is especially important in ophthalmic surgery or microsurgery. Moreover, biofilm in the miniature defects may not be removed during the sterilization process; which can become a source of infection for the patients.
Other metals that can be used for manufacturing surgical instruments include Titanium, Platinum, Palladium, Tantalum etc.
Conclusion: What are surgical instruments made of?
Surgical instruments are manufactured using a variety of metals including stainless steel, Tantalum, Platinum, Titanium and Palladium. The most widely used metal is stainless steel.