Symptoms & Causes

What are the symptoms of hip dysplasia?

Common symptoms of developmental dysplasia of the hip (DDH) may include:

  • The leg on the side of the dislocated hip may appear shorter.
  • The leg on the side of the dislocated hip may turn outward.
  • The folds in the skin of the thigh or buttocks may appear uneven.
  • The space between the legs may look wider than normal.

In hip dysplasia, the socket (acetabulum) is too shallow and the ligaments too loose, allowing the ball of the thigh bone (femoral head) to slip partially or completely in and out of the hip socket. The risk for hip dysplasia and hip instability increases with any situation that stretches the baby’s hip ligaments (an issue of stability) or causes the legs and hips to be positioned so that the ball of the thigh bone slips out of the hip socket (an issue of shape).

What causes hip dysplasia?

The exact cause of DDH is unknown, but it’s considered to be a "multifactorial trait," meaning there are many factors involved. The risk of developmental hip dysplasia is higher for:

  • children with a positive family history of DDH in a first-degree relative
  • females, who have looser ligaments than males
  • first-born babies, whose fit in the uterus is tighter than in later babies
  • breech babies, whose constrained position tends to strain the joint’s ligaments