Radiographic image of the right hip presenting 33% of subluxation (excluded from the study). The H-line passes through the triradiated cartilages of the hips (similar to the Hilgenreiner line), line B is drawn perpendicular to line H and on the acetabular ridge (similar to the Perkins line), Line C determines the medial limit of the femoral head and line A determines the lateral limit of the same. The percentage of migration was calculated as distance AB/AC x 100 = % of femur head migration (similar to that performed and described by Reimers, 1980).