Ultrasonographic findings of the normal hip of an infant

(A) Diagrammatic representation of an ultrasonographic landmark of a normal right hip.
(B) Diagram demonstrating alpha and beta angles. The alpha angle is the angle formed by the ossified lateral wall of the ilium (line 1 above) and the bony roof line (line 3 above). The beta angle is the angle formed by the ossified lateral wall of the ilium (line 1 above) and the cartilaginous roof line (line 2 above).