The value of the acetabular teardrop figure in assessing pediatric hip disorders.

We have observed that the acetabular teardrop figure provides extremely useful information about the development of the hip in young children. Normal development of the acetabulum is associated with progressive narrowing of the teardrop figure and development of a concave shape to its acetabular line. Anatomic and functional abnormalities of the hip can cause abnormalities of the teardrop figure, including absence of the acetabular line, persistent widening, and a V-shaped teardrop figure. In young children, these abnormalities can be reversed to some degree by stabilizing operations, but it is unusual to observe substantial change in appearance of the teardrop figure after a child is aged 8 years.