1. Lines drawn for measurement in developmental dysplasia of the hip
Lines drawn for measurement in developmental dysplasia of the hip. In the figure, the patient's left hip (on the right of the figure) is the subluxated one. A: Hilgenreiner line is a horizontal line of the pelvis, drawn between the triradiate cartilages. The proximal femoral ossification center should be below this line. B: Perkins line is a vertical line (perpendicular to Hilgenreiner line) drawn down from the lateral edge of the acetabulum. The femoral head ossification center, as well as the medial beak of the proximal metaphysis, should fall medial to this line. C: The acetabular index is the angle between Hilgenreiner line and a line joining the acetabular center (triradiate) with the acetabular edge as it intersects Perkins line. It measures acetabular depth and should be below 30 degrees by 1 year of age and below 25 degrees by 2 years of age. D: The center-edge angle is the angle between Perkins line and a line joining the lateral edge of the acetabulum with the center of the femoral head. It is a measure of lateral subluxation that becomes smaller as the hip subluxates laterally. Normal is 20 degrees or greater.
Source: Chapter 10. Pediatric Orthopedic Surgery, Current Diagnosis & Treatment in Orthopedics, 5e
Citation: Skinner HB, McMahon PJ. Current Diagnosis & Treatment in Orthopedics, 5e; 2014 Available at: Accessed: October 27, 2017
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