6 mo of age. Anteroposterior view of the pelvis - use of several classic lines drawn on itLineTypeLandmarksInterpretationHilgenreiner lineHorizontallineDrawn through the top of both triradiate cartilages (the clear area in the depth of the acetabulum).* Perpendicular to the Hilgenreiner line* Ossific nucleus of the femoral head should be located in the medial lower quadrant of the intersection of these two linesPerkins lineVerticallineThrough the most lateral ossified margin of the roof of the acetabulumShenton lineCurvedlineDrawn from the medial aspect of the femoral neck to the lower border of the superior pubic ramus* Line is a continuous contour - normal* Two separate arcs / "broken" - in DDHAcetabular indexAngleFormed between the Hilgenreiner line and a line drawn from the depth of the acetabular socket to the most lateral ossified margin of the roof of the acetabulum (angle measures the development of the osseous roof of the acetabulum)* Newborn, the acetabular index can be up to 40 degrees* By 4 months in the normal infant, it should be no more than 30 degreesIn older childCenter-edge angleAngleFormed at the juncture of the Perkins line and a line connecting the lateral margin of the acetabulum to the center of the femoral head* 6-13 years old, an angle >19 degrees - normal* >14 years and older, an angle >25 degrees - normal Treatment Goals: Obtain and maintain a concentric reduction of the femoral head within the acetabulum.AgeTreatment< 6 months of age* Triple diapers or abduction diapers no role.* Pavlik harness - In normal newborns with all degrees of hip dysplasia.* Other braces - von Rosen splint, Frejka pillow.* 1 and 6 mo of age - Pavlik harness (full-time basis for 6 weeks), hip instability resolves in 95% of cases.* 6 months of age, the failure rate for the Pavlik harness is >50% (increasingly active and crawling child).6 months to 2 years* Closed reductions under general anesthesia. And casting in human position of moderate flexion and abduction for 12 weeks.* The replaced by an abduction orthotic device for 2 months (until acetabular development is normal).* Failure to obtain a stable hip needs open reduction.Older than 2 years of age* Open reduction is usually necessary.Sequlae: Avascular necrosis of the Capital Femoral epiphysis (< 6 months of age), redislocation, residual subluxation, and acetabular dysplasia.">