Science & Technology in Action

8th Edition

Surgical Cutting Tools

Stryker

This lesson outlines the range of surgical cutting tools and the processes and materials used in making them. Tools that are used more than once must be easily sterilisable.
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Contains the full lesson along with a supporting toolkit, including teachers’ notes.

Lesson excerpt

Most surgery involves a certain amount of cutting of body tissues such as skin, muscle and bone. The more common surgical cutting instruments are scalpels, drills, burs, saws, scissors and rongeurs. Because of the ‘life or death’ nature of surgery, the reliability of surgical tools is very important. In this lesson we explore various aspects of the manufacture of these instruments including choice of materials, manufacturing processes, ease of use, resistance to corrosion and cleanability (‘Is it easily sterilised?’).

The effectiveness of surgical cutting instruments may be enhanced by ultrasonic and/ or electrical components enabling the surgeon to perform accurate and rapid dissection.

Choice of Materials
Surgical steel is the most commonly used material in the manufacture of surgical cutting tools. This is a type of stainless steel that is particularly resistant to scratches and to corrosion.

Steel is an alloy of iron and other elements, most commonly carbon (0.2% and 2.1%). The relatively small amount of carbon makes the steel about a hundred times stronger and harder than pure iron. However, ordinary steel is subject to corrosion (rust) and so would be unsuitable for medical use.

Stainless steel contains substantial amounts of chromium (10.5% or more). Steel used for domestic cutlery typically contains nickel (10%) along with chromium (18%). Unlike nickel plated steel, it does not rust if scratched.

 

Quiz questions

  1. All elements are alloys. false
  2. Steel is an alloy of iron with other elements. true
  3. Surgical steel corrodes very easily. false
  4. Surgical cutting instruments can have several parts. true
  5. Annealing is carried out to give cutting edges the correct level of hardness. true
  6. Softer materials are more brittle. false
  7. Epoxy glues are two-part glues that form a polymer as they set. true
  8. A bur is a type of saw. false
  9. Different metals in contact with the body can produce small voltages. true
  10. The chromium in surgical steel forms a relatively inert oxide that acts as a barrier between body tissues and the metal. true

Glossary of terms

Alloy
a mixture or solid solution composed of metals.
anneal
to heat and then slowly cool (metal, glass, etc.) in order to make it stronger
bone-cutting forceps
An instrument resembling a pair of pincers or tongs, used for grasping, manipulating, or extracting, especially such an instrument used by a surgeon.