31,000-year-old skeleton missing lower left leg is earliest known evidence of surgery, experts say

A 31,000-year-old skeleton missing its lower left leg and found in a remote Indonesian cave is believed to be the earliest known evidence of surgery, according to a peer-reviewed study that experts say rewrites understanding of human history.

An expedition team led by Australian and Indonesian archaeologists stumbled upon the skeletal remains while excavating a limestone cave in East Kalimantan, Borneo looking for ancient rock art in 2020.

The finding turned out to be evidence of the earliest known surgical amputation, pre-dating other discoveries of complex medical procedures across Eurasia by tens of thousands of years.

By measuring the ages of a tooth and burial sediment using radioisotope dating, the scientists estimated the remains to be about 31,000 years old.

Palaeopathological analysis of the remains revealed bony growths on the lower left leg indicative of healing and suggesting the leg was surgically amputated several years before burial.

He said the research team, which included scientists from the Indonesian Institution for Archaeology and Conservation, was examining ancient cultural deposits when they crossed stone markers in the ground revealing a burial site.

After 11 days of excavation, they found the skeleton of a young hunter-gatherer with a healed stump where its lower left leg and foot had been severed.

Maloney said the nature of the healing, including the clean stump showed it was caused by amputation and not an accident or animal attack.

Prior to this discovery, Maloney said it had been widely accepted that amputation was a guaranteed death sentence until about 10,000 years ago, when surgical procedures advanced with the development of large settled agricultural societies.

The previous oldest evidence of a successful amputation was a 7,000-year-old skeleton of an elderly farmer from stone age France. His left arm was amputated above the elbow.

Maloney said the stone age surgeon must have had detailed knowledge of anatomy, including veins, vessels and nerves, to avoid causing fatal blood loss and infection.

He said the successful operation suggested some form of intensive care, including regular disinfection post-operation.

Spriggs said it should not be surprising that stone age people could have developed an understanding of the internal workings of mammals through hunting, and had treatments for infection and injury.

He said they would have had to experiment with plant medicines and other treatments to stay alive.

The study was published in the journal Nature.