Inca Skull Surgery

  • By Melissa Salpietra
  • Posted 01.01.10
  • NOVA

The Inca were not only skilled engineers and warriors but also successful surgeons. Five hundred years ago, without the benefit of steel scalpels or antibiotics, the Inca performed a type of operation called trepanation—literally carving holes in patients' skulls. How did they do it, and why? In this audio slide show, bioarcheologist Valerie Andrushko of Southern Connecticut State University explains.

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See evidence of a radical surgical procedure common among the Inca 500 years ago.


Inca Skull Surgery

Posted January 1, 2010

VALERIE ANDRUSHKO: Bones are basically a record of an individual's life and a record of their death.

My name is Valerie Andrushko. I'm an assistant professor of anthropology at Southern Connecticut State University. The field of bioarchaeology centers on the study of human remains and their contexts. So we study the remains to look for any indications of disease, indications of injury, any kind of cultural practice apparent in the bones.

The bones that I study are from Cuzco, which was the capital of the Inca empire. The Inca were the last great Andean civilization. In studying the Inca burials from Cuzco, I've found several examples of cranial trauma, several examples of facial trauma. We see nasal fractures and, notably, a rise in the frequency of cranial trauma as the Inca rose to power.

This signals a rise in violent conflict. The Inca were known to use warfare as a mechanism of conquest, and it appears that this is reflected in the patterns we're seeing in the bones.

TEXT SLATE: Inca skulls also reveal evidence of trepanation, a practice that involved removing a part of the skull.

VALERIE ANDRUSHKO: Trepanation was practiced all over the world, but Peru appears to be sort of an epicenter. The reasons behind trepanation have been debated for many decades. What we were able to document in the Cuzco population is a very high correlation with cranial trauma.

So It seems that they were using trepanation to treat intra-cranial pressure, to literally remove a portion of the skull, thus releasing the pressure and negating the very serious complications caused by brain swelling. It's literally our earliest example of skull surgery.

This is surgery that was done without the modern conveniences of anesthesia, without antibiotics. It is certainly possible that individuals were conscious during this procedure.

It's still exactly which tools the Inca were using to practice this. The Tumi knife could have been used to cut the scalp, but it doesn't appear that it would have been as useful in cutting the cranial bone.

The hole that has been created by cutting away the bone, that never fills in. So, even in trepanations that have been healed for many years, we're never going to see bone that covers up that hole. Among Cuzco populations that we've studied, the success rate reaches nearly 90 percent, so 90 percent of the trepanations that we studied show significant healing.

The most extreme example of trepanation that I've seen is from a site called Qotakalli. In this case, the individual had seven trepanations. Six of these were well healed. The last one was a trepanation that the individual did not survive.

When we see skulls with four, five, six trepanations, it is somewhat of an enigma. Because trepanation was used to treat cranial trauma and possibly helped to alleviate seizures due to trauma, it's possible that Inca practitioners also tried to use trepanation to treat seizures of a non-traumatic origin.

Trepanation practitioners were taking care to avoid the musculature of the skull. They very clearly had an understanding of cranial anatomy, had an understanding of controlling bleeding and were quite advanced in this area. It shows the sort of innovative spirit of the Inca. They pursued this treatment. They likely passed down the knowledge of this treatment through the generations.

This is something that we see in many aspects of Inca culture, in their architecture, in their astronomy. I think it's something to be admired and intrigued by because it shows the innovative spirit of the human species.



Produced by
Melissa Salpietra


(all skull images, bones on lab table, various bones from Cusco, Qotakalli field site, Machu Picchu)
Courtesy Valerie Andrushko
(Andrushko teaching class)
Courtesy Isabel Chenoweth/Southern Connecticut State University
© YinYang/iStockphoto
(Depiction of King Atahualpa)
© North Wind Picture Archives via AP Images
(Inca warfare)
© 2009 NGHT, Inc. and WGBH Educational Foundation
(1490 trepanation)
© The Gallery Collection/Corbis
(Peruvian trepanation)
© Blue Lantern Studio/Corbis
(Tumi knife)
© AP Photo/Martin Mejla
(Inca man, Inca woman)
© National Geographic Television

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