Developmental dysplasia of the hip in female adult individual: Site Tres Cruces I, Salta, Argentina (Superior formative period, 400-1000 AD).

Developmental dysplasia of the hip (DDH) is a developmental defect that prevents normal articulation between the acetabulum and the femoral head. This is an unusual condition, with a prevalence of 1-2 per thousand, and with only two poorly described skeletons documented in South American paleopathological literature. In this work we report an individual with such a condition, from the archeological site Tres Cruces I (Quebrada del Toro, Salta, Argentina). Several radiocarbon dates and associated materials date it to the Superior Formative (400-1000 AD). The remains are of an adult female, who also has tabular oblique cranial modification. Through detection of abnormalities in the morphology of the femora and ossa coxae, a differential diagnosis was carried out. On the left hip joint the formation of a well-defined false acetabulum, without connection with the true one, was observed. The latter was shallow, triangular, with an irregular base. The left os coxae showed a wider greater sciatic notch angle. The right os coxae exhibited a false acetabulum connected with the true one. Both femora presented a small femoral head, flat and mushroom-shaped, with shortening of the neck. These features were more pronounced on the right-side elements. On the basis of the aforementioned, a presumptive diagnosis of bilateral developmental dysplasia of the hip with complete dislocation on both sides was established.