Skeletal dysplasia of an adult male from medieval Łekno in Poland, Central Europe

The skeletal dysplasias are a group of more than 450 heritable disorders that affect bone and cartilage, along with muscles, tendons, and ligaments. Achondroplasia is one of the most common skeletal dysplasias in both current and past populations. It can be transmitted intergenerationally, or it can result from a mutation. This paper aims to describe the lesions visible on the skeleton of a 30–45 year old male with achondroplasia, who lived during the 9th–11th centuries AD (medieval period) in Łekno, Poland. The Łekno settlement complex (Site 3) includes a cemetery with approximately 400 burials of monks and local lay people. Macroscopic examination facilitated a differential diagnosis that identified a probable case of achondroplastic dwarfism, combined with Léri–Weill dyschondrosteosis and ulnar hemimelia. This is the first case of dwarfism in the bioarchaeological literature that had been documented and visualized using 3D modelings, which were used to show quantitative differences in articular surface areas between the achondroplastic individual and contemporaries of normal stature. Ulnar hemimelia is most commonly seen today as a component of skeletal dysplasias. The right ulna of this male was significantly shorter than the right radius and the left ulna. It is probable that he had multiple skeletal dysplasia (achondroplasia, Léri–Weill dyschondrosteosis) as well as ulnar hemimelia as a component of achondroplasia. The combination of these disorders has not been previously reported in the bioarchaeological literature, and this individual is also the first case of achondroplasia and Léri–Weill dyschondrosteosis from the medieval period in Central Europe. As such, this example is used here to provide insights on a variety of different diseases, syndromes, and conditions in Polish medieval populations and that will help in future identification of rare diseases from archaeological sites.