Fig. 6.
Normal variations of acetabular anatomy are demonstrated on an anteroposterior pelvic radiograph in two children with juvenile idiopathic arthritis. a Radiograph in a 10-year-old boy shows a small defect at the lateral aspect of the acetabular roof (arrow). b Radiograph in a different 10-year-old boy shows mild sclerosis at the lateral and weight-bearing areas of the acetabular roof (arrow)