Asian Journal of Paleopathology Vol.7, 13–19, 2026

Received: November 12, 2025

Accepted: November 27, 2025

Published online: December 12, 2025

DOI: 10.32247/ajp2025.7.05

Case Study

A paleopathological case of vertebral fusion secondary to a compression fracture in Yayoi human remains from the Hamago site, Nagasaki, Japan

Daisuke Kubo, Daisuke Endo, Kazunobu Saiki, Toshiyuki Tsurumoto, Keiko Ogami-Takamura

Abstract

Vertebral fusion in archaeological human remains is not uncommon, yet detailed reports of trauma-induced cases are limited. This study examines an adult female from the Yayoi-period Hamagō site in Nagasaki Prefecture, Japan, with vertebral fusion associated with a compression fracture. Macroscopic observation revealed fusion of Th12–L2 on the left side of the vertebral bodies through osteophyte formation, accompanied by marked collapse of L1. Computed tomography showed that the bony bridges consist predominantly of dense bone. The fused segment exhibits approximately 15–20° of kyphosis, 30° of leftward inclination, and a 5-mm rightward and posterior displacement of L1 relative to L2. No evidence of tuberculosis, ankylosing spondylitis, or diffuse idiopathic skeletal hyperostosis (DISH) was found, and degenerative changes elsewhere were minimal. Considering these observations, together with the fact that L1 is a common site of traumatic compression fractures, the fusion is most consistent with a secondary response to such an injury. Furthermore, the L1 vertebral arch shows marked bilateral asymmetry; however, because no evidence of fracture was observed in the arch, this asymmetry is plausibly interpreted as a pre-existing developmental or acquired condition rather than a sequela of the trauma.

 Key words

Fused vertebrae, vertebral compression fracture, thoracolumbar fracture, trauma, Gotō Islands