Encyclopedia of the Incas

Inca empire show higher frequencies of all types of skeletal indicators of
physiological stress, but it appears that Inca imperial practices did not
dramatically impact diet or health in the communities studied to date. Bone
chemistry studies of carbon and nitrogen in the diets of people from one
provincial community indicate that diet was nutritionally adequate. Human
remains from the provinces show significantly higher frequencies of
degenerative joint disease in comparison to people from the core and peripheries
of Cuzco, which suggests that workloads and tribute demands may have been
higher in the provinces.
Broken bones were fairly common during Inca times and were typically caused
by accidents or occupational hazards. Nonlethal and healed injuries to the
cranium indicate that some people may have participated in ritualized battles or
intergroup conflicts, but lethal perimortem injuries, which would have occurred
around the time of death and were often associated with pitched battles and
warfare, are relatively rare in the Cuzco region and only slightly more common
in the provinces.
Accounts by the chroniclers detail how Inca medical specialists applied herbs
and poultices to fractures and stitched or set these injuries. The Incas were also
adept at the surgical removal of part of the cranium, a practice known as
trepanation, that has been studied extensively and which was likely undertaken
to treat cranial trauma, infection of the mastoid of the temporal bone, epilepsy,
and non-epileptic seizure disorders. Cuzco Inca practitioners of trepanation had
success rates of approximately 80 percent and they were more successful in their
surgeries than pre-Inca surgeons. Their success was likely due to the use of
antiseptics, such as balsam, saponins, cinnamic acid, and tannins, as well as their
standardized surgical methods and advanced knowledge of cranial anatomy.
Cuzco trepanations were typically two of the four common types observed in the
Central Andes, either circular grooving or scraping methods. In circular
grooving, a circular or ovoid incision was made and a round plug of cranial bone
would be removed. With the scraping method, a wide swath of cranial bone was
scraped from the ectocranial surface and a smaller portion of bone was scraped
from the endocranial surface.
Similar to other Central Andean prehistoric peoples, the Incas likely suffered
from chronic and acute infectious diseases, such as tuberculosis, the non-
venereal forms of treponemal disease, and different forms of pneumonia.
Probable cases of tuberculosis and treponemal disease have been differentially
diagnosed from bioarchaeological investigations of Inca skeletons, but they have