Developmental Dysplasia of the Hip What Is It? In a normal hip
joint, the rounded top of the thigh bone (femur) fits into a
cup-shaped socket in the pelvis called the acetabulum. This type
of joint is called a ball-and-socket joint. In developmental
dysplasia of the hip, the top of the femur moves in and out of
the socket either part way or all the way. When it moves all the
way out of the socket, it is called a dislocation. This happens
when the ligaments that hold the two bones together are very
loose or because the cup-shaped socket is not deep enough. This
condition usually is present at birth. But it can develop during
infancy or childhood. If the bones in the joint are not in the
right place, the hip and femur can't grow normally. This can
lead to: - A shortened leg - Difficulty walking - Long-term pain
In an infant, developmental dysplasia of the hip can result in
the following: - One leg is shorter than the other. - The right
and left kneecaps are not at the same level when you look at
both legs at th