A Probable Case of Multiple Osteochondromas With Madelung‐Type Deformity in Human Remains From the 7th to 10th Centuries in Japan

ABSTRACT We present a rare paleopathological case of probable multiple osteochondromas (MO) with an associated Madelung‐type deformity, identified in an adult male skeleton excavated from the Hasekouji‐Shuhen site in Kamakura, Japan, dated from the 7th–10th centuries ad . The individual exhibited multiple exostotic lesions, primarily affecting the distal femora, proximal tibiae, and fibulae, along with a pronounced right‐sided forearm deformity characterized by shortening, bowing, and articular displacement. MO can be supported by differential diagnosis, which is based on lesion morphology, distribution, and bilateral expression, while the forearm changes are consistent with a secondary, acquired Madelung‐type deformity resulting from growth plate disturbance. This case represents the earliest probable example of MO with associated Madelung‐type deformity in the Asian‐Pacific region and only the third such case reported globally. Despite limitations, including the absence of genetic or histological analysis, the findings contribute valuable insight into rare skeletal dysplasias in ancient populations.