Three cases of developmental dysplasia of the hip on partially mummified human remains (Roccapelago, Modena, 18th Century): a study of palaeopathological indicators through direct analysis and 3D virtual models

Developmental dysplasia of the hip (DDH) is caused by a delay in the development of the acetabular cavity, leading to an anomaly in the angle of the acetabular roof. As a result, the femoral head and the acetabular cavity do not interact normally. The identification of three cases of DDH among the remains discovered in the most recent unit from the crypt at Roccapelago (Modena, Italy) enabled us to discuss the presence of DDH in this region during the 18th century. All three cases are bilateral and Dunn class I, two have been identified as male and one as female. These DDH cases are very likely mainly due to mechanical factors such as the breech position of the foetus, perhaps associated with birth order. But given their overall similarity, they may also have resulted from the practice of swaddling new-borns. In addition, current data from the Italian Ministry of Health suggests that the incidence of DDH has remained stable in this region from the 18th century to the present. The ongoing study of remains from earlier units should bring a better understanding of the particular prevalence of DDH at Roccapelago.