Craniotomy as a prehistoric medical practice: a case of antemortem cranial trepanation in Southern Siberia in the late Bronze age

Complete trepanation with the removal of the inner bone plate was studied on a cranium of a male aged ca 35 from a Late Bronze Age burial at Anzhevka in the Krasnoyarsk-Kansk forest-steppe, dating to 1000-700 BC. Certain burials including that with a trephined cranium reveal traces of post-funerary rituals. The individual displays the Paleosiberian (Baikal) combination of craniometric and dental characteristics. Results of the macro- and microscopic analysis of the affected area, along with multislice computed tomography (MSCT), suggest that the trepanation was performed to treat osteomyelitis of the parietal bone with an epidural abscess (empyema), caused by an open depressed fracture of the left parietal bone, inflicted with a tool having a small contact area. In modern forensic practice, such perforations are attributed to hammer blows. This would explain the absence of linear fractures of the parietal bone around the trepanation zone. Craniotomy with the removal of the osteomyelitw focus and the emptying of the epidural abscess led to a prolonged preservation of the patient’s life. Results of a traceological analysis suggest that the aperture was made by scraping, and a thin tetrahedral tool was used to remove the bone fragment. Possibly the use of bronze instruments, known to have antiseptic properties, helped the ancient healer to cope with an advanced infectious process.