Amongst the list of the most useful tools in human history, the knife is usually at the top. The knife is hypothesized to have existed for more than 2 million years, longer than modern humans have walked the Earth. It’s evolved, changing form, to meet our needs.
Evidence of knives used in medicine may be traced to the Mesolithic period around 8000 BC. Flint knives were used as scrapers to cut through the skull in trepanation.
Hippocrates may have been the first to describe the surgical knife, termed the “macairion”, a smaller version of a Lacedaemonian sword called a “machaira”. “Scalpel” comes from the Latin word, “scallpellus”. Modern surgeons have embraced the term “scalpel” over “knife”. “Knife” connotes danger and is more likened to a weapon associated with mutilation and death. If anyone else takes a knife to another person, it’s a criminal attack. Furthermore, a “knife” can be used by anybody, but a “scalpel” is only used by a surgeon. Wounds happen on the battlefield while incisions happen in the operating room, so “scalpel” implies security associated with healing.
Interestingly, the shape of the scalpel likely has not changed much over time.
How the scalpel was made has varied over time.
Blades were initially composed of sharpened stones like flint, jade or obsidian, but metal blades replaced them. Copper in 3500 BC, bronze and iron in 1400 BC.
Roman surgeons relied on armorers who made cutlery for wartime as well. Surgical instrument-making, as a profession, was noted in the 18th century in England, France, Holland and Germany. America historically has always imported knives. For a time period, barber-surgeons were prominent in the US, embellishing their scalpels as part of the art of their craft. After the 1st and 2nd World Wars, the American industry caught up in manufacturing leadership.
As elective surgery rose to prominence, the individual needs out of a scalpel have morphed and now must meet certain requirements. The most important is sharpness. Other features like shape, balance, uniformity and dependability are critical.
Years ago, most scalpels were made of nickel or chromium-plated carbon steel. Stainless steel later took over, due to its reusability and resistance to corrosion. However, obsidian… a type of volcanic glass… has re-emerged. Reusability is cost-efficient, but sharpness produces cleaner and more precise cuts with quicker healing and less scarring. Obsidian can produce cutting edges many times finer than the best steel… and obsidian blades first produced about 2,500 years ago in Mesoamerica can still cut today. Angstroms are a unit of measurement between atomic planes in a crystal. The smaller the angstrom, the finer the blade.
A household razor blade (King Gillette produced the first safety shaving blade in 1904) is about 300-600 angstroms, while an obsidian blade is about 30 angstroms.
Under a microscope, an obsidian scalpel divides individual cells in half, while steel scalpel incisions look like they were made by a chainsaw. Even handling an obsidian scalpel takes great care because one can unknowingly cut themselves without pain because the laceration is so fine.