Fig. 2

Radiological evaluation. a The radiographic indices used for the evaluation of the hip are shown. O = center of the femoral head; Line A = line between the teardrops on both sides; Circle A = circle passing through three points set arbitrarily in the acetabular joint surface; Circle B = circle passing through three points set arbitrarily in the femoral head. Scale bar, 5 mm. b T1-weighted magnetic resonance imaging (MRI) image illustrating the method used to measure the length of the low-intensity band. Scale bar, 10 mm. CE, center-edge