Presentation
Delayed walking.
Patient Data
bilateral shallow and underdeveloped acetabula
bilateral notching at the superior acetabular margins
bilateral superolateral displacement of femoral epiphyses
bilateral interrupted Shenton line and acetabular angle
Both femoral epiphyses are located in superolateral quadrant to the intersection of Hilgenreiner (Horizontal) and Perkin (Perpendicular) lines (white lines).
Disrupted Shenton line bilaterally (green line).
Abnormal acetabular angle bilaterally (yellow lines).
right acetabular angle measures 45º
left acetabular angle measures 40º
Case Discussion
Radiographic features of a bilateral developmental dysplasia of the hip (DDH) with associated dislocation. It is more common in females (F:M 8:1). It is bilateral in about 20% of cases.
Normally
Hilgenreiner line is used to form Perkin line and measuring acetabular angle
Perkin line should intersect the lateral most aspect of the acetabular roof
both femoral epiphyses are centred in the inferomedial quadrant
acetabular angle should be <30º at birth and <22º at and beyond 1 year